WILEY     ENGINEERING    SERIES 

OXY-ACETYLENE 
WELDING    MANUAL 


BY 


LIEUT.  LORN  CAMPBELL,  JR.,  U.S.A. 


ncer  in  Charge  of  Welding  Instruction, 
Ordnance  Department,  U.S.  Army. 


TOTAL   ISSUE,   FIVE    THOUSAND 


NEW    YORK 

JOHN  WILEY  &  SONS,  Inc. 

LONDON;  CHAPMAN  &  HALL,  LIMITED 
1919 


Copyright,  1919 

BY 
LORN  CAMPBELL 


Copyrighted  in  Great  Britain 


PRESS  OF 

BRAUNWORTH   &   CO. 

5/2O  BOOK   MANUFACTURERS 

BROOKLYN,   N.  Y. 


PREFACE 


(1)  THE   oxy-acetylene  method   of   welding   and   cutting 
metals  has  of   late  been    receiving    considerable  attention. 
Its  tremendous  power  of  creating,  repairing  and  destroying 
the  work  of  man  has  been  but  recently  recognized  in  its 
broadest  sense,   and  the  demand  for  operators,   skilled  in 
the  manipulation  of  this  apparatus,  which  always  has  been 
far  in  excess  of  the  supply,  now  knows  no  limit.     Many 
authorities  have   set   forth   their  views   and   theories  upon 
this  subject,  in  America  and  also  in  foreign  countries.     These 
have  been  published  from  time  to  time  in  many  of  the  leading 
periodicals  and  magazines,  as  well  as  in  book  form.     It  seems 
the  purpose  of  most  of  these  works  has  been  to  advance 
the  operators  who  already  have  a  smattering  knowledge  of 
this  art,  or  to  present  to  the  purchaser  of  apparatus  a  set 
of  operating  instructions. 

(2)  It  is  singular  indeed  that  a  school  manual,  devoted 
exclusively   to   the  instruction  of  the  beginner,  which  will 
serve  as  an  aid  to  the  instructor  as  well  as  to  the  student, 
has  not  yet  been  put  forth.     It  cannot  be  said  that  there 
is  not  a  demand  for  such.     Recently  there  seems   to  have 
been  a  mushroom  growth  of  welding  classes.     The  majority 
of  the  vocational  schools,  colleges,  night  schools,  and  auto- 
mobile  schools   have   all   entered    the   instruction    in    oxy- 
acetylene  welding  on  their  rolls  and  each  is  attempting  to 
instruct   in   an    entirely  different   manner   from    the   other. 


423684 


vi  PREFACE 

There  can  be  no  question  as  to  the  expediency  of  affording 
the  educational  institutions  a  systematic  as  well  as  a  stand- 
ardized method  of  instructing.  But  the  books  and  articles 
of  the  nature  mentioned  are  not  suited  to  this  purpose, 
and  were  not  designed  for  it.  A  school-book  is  wanted; 
something  to  be  used  in  the  classroom,  to  be  employed  as 
a  reference  in  the  shop  practice,  to  be  studied  for  what  it 
contains,  and  to  indicate  further  lines  of  research,  where 
such  are  required. 

(3)  To  meet   this  demand,   the  present"  Manual"  has 
been  written  to  serve  the  instructor  as  well  as  the  student. 
In    its    preparation    many    books,    both    well-known    and 
obscure,    have    been    examined    and  the  methods   of  shop 
instruction  have  been  carefully  studied  by  the  author. 

(4)  It  has  been  found  that  regardless  of  how  fast  the 
ground  may  be  covered  in  the  lecture  room,  the  average 
student's  power  of  assimilation  is  limited  and  considerable 
time  has  been  spent  in  determining  this  ratio  and  applying 
it  between  the  lecture  subjects  and  shop  work. 

(5)  It  must  be  remembered  that  while  the  chapters  com- 
prising the  theoretical  part  of  this  welding  manual  follow 
in  the  order  given,  the  actual  shop  practice,  as  previously 
mentioned,  is  the  most  important. 

(6)  Kindly   aid   has   been   received   from   many   sources. 
Granjon  &  Rosemberg,  Kautney,  M.  Keith  Dunham,  S.  W. 
Miller,  Henry  Cave,  C.  J.  Nyquist,  P.  F.  Willis,  Ben  K. 
Smith,  and  others  have  embodied  in  their  writings  many 
excellent  ideas,  which  have  assisted  the  author  in  bringing 
out   certain   points   advantageously.     The   following  manu- 
facturers are  to  be  given  credit  for  many  of  the  illustrations: 

The  Oxweld  Acetylene  Co.,  Newark,  N.  J. 

The  United  States  Welding  Co.,  Minneapolis,  Minn. 

The  Bastian  Blessing  Co.,  Chicago,  111. 


PREFACE  vii 

The  Linde  Air  Products  Co.,  New  York  City. 

The  General  Welding  &  Equipment  Co.,  Boston,  Mass. 

The  Messer  Manufacturing  Co.,  Philadelphia,  Pa. 

The  Alexander  Milburn  Co.,  Baltimore,  Maryland. 

The  Torchweld  Equipment  Co.,  Chicago,  I1L> 

The  Davis-Bournonville  Co.,  Jersey  City,  N.  J. 

The  K.  G.  Welding  Co.,  New  York  City. 

The  Chicago  Eye  Shield  Co.,  Chicago,  111. 

The  Commercial  Acetylene  Supply  Co.,  New  York  City. 

The  Welding  Engineer,  Chicago,  111. 

The  Journal  of  Acetylene  Welding,  Chicago,  111. 


NOTE. — Lieut.  Campbell  offers  his  services  without  charge  to  anyone 
interested  in  this  method  of  welding  and  may  be  addressed  care  of  JOHN- 
WILEY  &  SONS,  INC.,  Publishers,  432  Fourth  Avenue,  New  York  City. 


WILEY  ENGINEERING  SERIES 


THE  Wiley  Engineering  Series  will  embrace  books  devoted 
to  single  subjects.  The  object  of  the  Series  is  to  place  in  the 
hands  of  the  reader  all  the  essential  information  regarding 
the  particular  subject  in  which  he  may  be  interested. 
Extraneous  topics  are  excluded,  and  the  contents  of  each 
book  are  confined  to  the  field  indicated  by  its  title. 

It  has  been  considered  advisable  to  make  these  books 
manuals  of  practice,  rather  than  theoretical  discussions  of  the 
subjects  treated.  The  theory  is  fully  discussed  in  text-books, 
hence  the  engineer  who  has  previously  mastered  it  there,  is, 
as  a  rule,  more  interested  in  the  practice.  The  Wiley  En- 
gineering Series  therefore  will  present  the  most  approved 
practice,  with  only  such  theoretical  discussion  as  may  be 
necessary  to  elucidate  such  practice. 


CONTENTS 


PAGE 

INTRODUCTION i 

I.  APPARATUS 19 

IT.  OPERATION 27 

III.  SHOP  EQUIPMENT 39 

IV.  APPARATUS  REPAIRS 44 

V.  PREHEATING  AGENCIES 51 

VI.  PART  ONE — WELDING  OF  CAST  IRON 58 

PART  Two — WELDING  OF  CAST  IRON 67 

PART  THREE — WELDING  OF  CAST  IRON 70 

PART  FOUR — WELDING  OF  CAST  IRON 75 

VII.  PART  ONE — STEEL  WELDING 81 

PART  Two — STEEL  WELDING 87 

PART  THREE — STEEL  WELDING 92 

PART  FOUR — STEEL  WELDING        .       .              97 

VIII.  BRASS  WELDING 106 

IX.  PART  ONE — ALUMINUM  WELDING 109 

PART  Two — ALUMINUM  WELDING 113 

PART  THREE— ALUMINUM  WELDING 118 

X.  WELDING  OF  MALLEABLE  IRON 120 

XI.   OXY-ACETYLENE   CUTTING 125 

XII.  CARBON  BURNING 135 

GLOSSARY .  145 

LECTURES 149 

INDEX ' .       .   167 


ix 


Oxy-Acetylene  Welding  Manual 


INTRODUCTION 

(i)  WHEN  choosing  a  life  vocation,  one  generally  views 
the  possibilities  it  has  to  offer  and  delves  deeply  into  these, 
previous  to  making  a  decision.  It  is  therefore  thought 
advisable  at  this  time  to  present  the  student  with  an  idea 
of  what  is  meant  by  oxy-acetylene  welding  and  cutting; 
how  it  is  applied;  the  possibilities  and  advantages  attached 
to  such  an  art. 

(2)  Acetylene  gas,  when  burned  with  a  proper  portion 
of  oxygen  gas,  produces  an  extremely  hot  flame,  in  fact, 
the  hottest  flame  known.  Its  temperature  is  over  6000 
degrees  Fahrenheit.  With  this  flame  it  is  possible  to  bring 
any  of  the  so-called  commercial  metals,  namely:  cast  iron, 
steel,  copper,  and  aluminum,  to  a  molten  state  and  cause 
a  fusion  of  two  pieces  of  like  metals  in  such  a  manner  that 
the  point  of  fusion  will  very  closely  approach  the  strength 
of  the  metal  fused.  If  more  metal  of  like  nature  is  added, 
the  union  is  made  even  stronger  than  the  original.  This 
method  is  called  oxy-acetylene  welding  and  differs  from 
what  the  average  layman  considers  welding  in  the  black- 
smith's forge,  insomuch  that  there  is  no  blow  struck  to 
assist  fusion  in  this  process.  And  while  the  forge  method 
is  limited  to  wrought  iron  and  steel  which  is  detachable 


2V  j  it*i     JOXY4ACETYLENE  WELDING  MANUAL 


INTRODUCTION 


and  of  restricted  size  and  shape,  the  oxy-acetylene  process 
has,  practically  speaking,  no  such  limitations.    d 

(3)  Manufacturers    in    the    metal- working    world    were 
very  slow  to  grasp  the  real  significance  of  this  important 
process,  until  the  operators  began  demonstrating  some  of 
its   possibilities.     At   the   present   time,   however,    there   is 
hardly  a  metal  barrel  or  tank 

manufacturer  who  has  not 
discarded  the  old  method  of 
producing  costly  leaky,  riv- 
eted drums  and  containers, 
for  this  modern  fusing  proc- 
ess. The  manufacturers  of 
fire-proof  doors  and  windows, 
cooking  utensils,  seamless  pipe 
and  tubing,  office  furniture 
and  what  not,  are  now  vir- 
tually dependent  upon  the 
welding  torch  at  every  turn. 

(4)  As  a  repairing  agent, 
the    welding    torch    has    no 
rival.     Whether  it  is  a  cast- 
ing  of   iron,  steel,  brass,  or       "  "^r^ 

aluminum    that    has      broken  ;  (Courtesy  of  the  Oxwela  Acetylene  Co.) 

a    boiler     or    tank    that    has   FlG-  2~ In  Enameled  Products  for  the 

Kitchen  the  Weld  is  Fast  Replacing 

worn   away  in   spots,  or  an  -,-....      D     .          ,  c  v 

J  '  the  Riveting,  Brazing,  and  Soldering 

error   on    the    part    of    en-      of  the  Light  Sheet  Metal  Seams, 
gineer,  foundryman   or   ma- 
chinist, the    part    can    generally  be    reclaimed    and    made 
stronger  than  originally.     To-day  practically  no  manufac- 
turing concern  that  is  dependent  upon  metallic  machinery 
could  think  of  being  deprived  of  its  oxy-acetylene  apparatus, 
once  having  learned  its  worth.     In  the  not  far  distant  past, 
were  a  gear  or  some  casting  to  break,  it  probably  meant  closing 


4  OXY-ACETYLENE  WELDING  MANUAL 

down  the  entire  plant  until  a  new  part  could  be  obtained, 
which,  whether  the  source  of  supply  were  near  or  at  a  long 
distance,  would  mean  costly  delay.  With  oxy-acetylene 
equipment  and  an  efficient  operator  on  hand,  almost  every 
emergency  is  provided  for. 

(5)  If  an  automobile  owner  breaks  a  frame,  he  does  not 
consider  replacing  it  with  a  new  one,  as  the  labor  alone  for 


(Courtesy  of  the  Oxweld  Acetylene  Co.) 
FIG.  3. — Welding  Broken  Frame  of  5-ton  Automobile  Truck. 


stripping  his  machine  and  setting  it  up  again,  not  to  men- 
tion the  cost  of  the  new  frame  and  the  time  required  for 
this  operation,  is  prohibitive.  Rather,  he  has  his  car  taken 
to  the  nearest  welder  or  his  portable  apparatus  to  the  car 
and  the  job  is  completed  within  thirty  or  forty  minutes, 
with  the  frame  at  the  point  of  the  break  made  stronger 
than  ever.  Locomotive  frames  are  handled  in  much  the 


INTRODUCTION  5 

same  manner,  only  more  time  is  required  and  perhaps  extra 
operators,  but  the  important  point  to  be  brought  out  is 
the  fact  that  on  many  jobs  no  dismantling  is  required  and 
the  repair  is  permanently  and  quickly  executed. 

(6)  An  interesting  example  of  the  true  worth  of  welding 
was  brought  to  the  attention  of  the  public  when  the  United 


FIG.  4. — Staff  of  Instructors  at  the  Ordnance  Welding  School,  U.  S.  A. 

States  entered  the  European  War,  and  all  the  interned 
German  vessels,  which  had  been  greatly  damaged  by  the 
orders  of  their  commanding  officers,  were  restored  to  working 
condition  with  the  oxy-acetylene  and  electric  welding  process. 
This  was  considered  impossible  by  many  engineers  not  fa- 
miliar with  the  process,  insomuch  as  they  looked  upon  oxy- 
acetylene  welding  as  applicable  only  to  small  parts  and 


6  OXY-ACETYLENE  WELDING  MANUAL 

here  some  of  the  sections  which  had  been  blown  or  struck 
out  of  the  cast  cylinders,  etc.,  weighed  many  hundreds  of 
pounds.  In  many  instances  the  ribs  of  these  same  vessels 
were  cut  most  of  their  depth,  but  these  were  restored  to 
working  order  in  a  remarkably  short  time  and  the  results 
were  more  convincing  than  any  words. 

(7)  Cutting  with  the  oxy-acetylene  process  is  just  the 
opposite  from  that  of  welding.     The  latter  might  be  con- 
sidered  constructive   and   the   former   destructive.     In   the 
case  of  welding,  two  parts  are  brought  to  a  molten  condition 
along  the  line  to  be  joined  and  both  fused  together.     Whereas 
in    cutting,    one   piece  of   metal,  when    brought  to    a   red 
heat,  is  cut  in  two  by  an  oxidizing  flame.     Cutting  has  not 
the  wide  scope  that  welding  has,  for  it  can  only  be  applied 
successfully  at  the  present  day  to  wrought  iron,  rolled  and 
cast  steel.     While  it  is  limited  in  its  scope,   the  speed  of 
this  process  in  severing  large  masses  of  metal  is  very  spec- 
tacular and  appeals  forcibly  to  the  observer. 

(8)  Probably    the   world's   first   awakening   to    the   real 
meaning   of   oxy-acetylene    cutting   came   when    the   U.    S. 
battleship  "  Maine,"  was  being  taken  from  Havana  Harbor. 
All  the  heavy  armor  plate  and  seemingly  immovable  wreck- 
age was   cut  into   small   sections  which   could  be  handled 
easily.     This  was  all  accomplished  with  the  cutting  torch, 
which  seems  to  eat  its  way  through  metal  with  the  same 
ease  that  a  hot  knife  goes  through  butter. 

(9)  Before  and  since  the  time  of  the  "  Maine,"  the  cutting 
torch   has   been   accomplishing   wonderful   feats.     In   every 
scrap  yard,  old  boilers  and  the  like  are  being  cut  into  fur- 
nace size;    speeding   up   the  production  in   answer   to   the 
world's  cry  for  more  metal.     The  wreckage  on  railroads  and 
buildings    using    steel    reinforcements    is    being    cleared    in 
hours,  with  the  aid  of  the  cutting  torch,  where  it  required 
days  by  other  methods.     Most  of  the  fire  departments  in 


INTRODUCTION 


the  larger  cities  now  carry  the  cutting  torch  as  part  df  their 
equipment,  and  to  it  has  been  credited  the  saving  of  many 
lives,  by  its  timely  cutting  away  of  steel  doors,  bars  or  barriers 
which  prevented  escape.  Much  of  the  plate  in  this  country's 


(Courtesy  of  the  Oxweld  Acetylene  Co.) 
FIG.  5. — Fireman  Cutting  |-inch  Steel  Fire  Door  with  Portable  Apparatus. 

shipbuilding  yards  is  being  cut  to  size  right  on  the  job,  and 
the  function  of  this  torch  in  cutting  off  risers  measuring 
from  one  to  thirty-six  inches  in  diameter  in  the  foundry 
seems  only  to  be  of  secondary  importance  in  comparison  with 


8  OXY-ACETYLENE  WELDING  MANUAL 

some  of  its  other  uses.  In  order  to  transport  some  of  tf 
largest  inland  lake  boats  which  were  much  too  long  to  pai 
through  the  locks,  to  the  sea,  they  were  cut  in  parts,  tran 
ported,  and  later  welded  together  and  placed  in  service. 

(10)  It  is  not  only  possible  to  keep  a  cutting  torch  bun 
ing  under  water,  but  it  can  also  be  made  to  cut.  Coi 
tracting  companies  are  cutting  off  their  piling  under  wat< 
and  it  has  been  known  that  in  European  ports  cutting  hi 


(Courtesy  of  Itie  Acetylene  Journal  Publishing  Co.) 

FIG.  6. — Welders  of  the  Signal  Corps,  U.  S.  Army,  in  Action. 

been  successfully  accomplished  at  a  depth  of  thirty  feet 
A  special  torch  is  employed  by  submarines  to  cut  nets  unde 
water. 

(n)  In  reviewing  the  oxy-acetylene  welding  and  cuttinj 
process,  we  find  that  its  growth  is  one  of  the  most  remarkabl 
the  world  has  ever  witnessed.  About  1907  saw  its  industria 
birth  and  since  that  time  it  has  advanced  by  leaps  am 
bounds,  rivaling  the  automobile  industry  in  its  progress 


INTRODUCTION 


9 


despite  the  opposition  and  criticism  levied  at  it  by  workers 
of  other  trades  and  its  careless  and  unskilled  manipulation. 
(12)  It  is  quite  impossible  to  present  anything  like  a 


(Courtesy  of  the  Acetylene  Journal  Publishing  Co.) 

FIG.  6a. — Welders  of  the  Signal  Corps,  U.  S.  Army,  in  Action. 


complete  list  of  the  applications  of  this  process,  but  a  few 
of  its  general  uses  are  here  enumerated: 

(A)  Airplane  Construction. — Welding  of  frames,  sockets, 
water  and  gasoline  tanks,  water  jackets  and  valve  cages  to 


10  OXY-ACETYLENE  WELDING  MANUAL 

cylinders,  intake  and  exhaust  manifolds  and  connections, 
spark  plug  thimbles  and  the  repair  of  aluminum  crank 
cases,  etc. 

(B)  Automobile  Manufacture. — Welding  of  steel  and  alu- 
minum bodies,  transmission  and  rear  axle  housings,  crank- 
shafts, cylinders,  gears,  manifolds,  pinions,  crank  cases,  valves, 


(Courtesy  of  the  Oxweld  Acetylene  Co  ) 

FIG.  7. — Welding  a  2 -foot  Length  of  New  Shafting  on  the  End  of  a  Motor 
Shaft  2  Inches  in  Diameter. 

rims,    mufflers,    frames,    fenders,    wind-shield    tubings,    and 
uprights,  etc. 

(C)  Boiler  Shops. — Welding  and  building  up  worn  spots 
around    hand-hold    plates,    repairing    cracks    and    checked 
portions  of  fire  boxes,  retipping  flues,  connections,  etc. 

(D)  Brass   and   Copper. — Welding   kettles,    vats,    tanks, 


INTRODUCTION 


11 


stills,    floats,    cooking    utensils,    manifolds,    water    jackets, 
electrical  and  chemical  wares,  etc. 

(E)  Commercial    Welding. — Reclamation    service    on    all 
kinds  of  metals,  quick  and  permanent  repairs  on  all  broken 
parts  of  machinery. 

(F)  Electric  Railway. — Welding  air  receivers  on  air-brake 
systems,  building  up  shafts,  bonding  the  rails,  motor  housings, 


(Courtesy  of  the  Torchweld  Equipment  Co.) 

FIG.  8. — This  is  a  Steel  Tank,  Made  of  f-inch  Plate,  which  Measures  30  Feet 
Long  and  8  Feet  in  Diameter,  Fused  into  One  Piece  by  the  Welding  Torch. 


worn  boxes,  reclaiming  gears  and  broken  trucks,  steel  trolley 
wires,  etc. 

(G)  Forge  Shop. — Welding  complicated  parts  which  can 
not  be  conveniently  handled  in  the  forge. 

(H)  Foundries. — Welding  up  blowholes,  porous  spots,  and 
reclaiming  castings  in  general.  The  cutting  off  of  risers, 
gates,  and  heads  on  steel  castings. 


12 


OXY-ACETYLENE  WELDING  MANUAL 


(I)  Lead   Burning.— Lead   pipe   joints,    storage   battery 
connections  and  repairs,  lead  linings  in  vats,  etc. 


(Courtesy  of  Ben  K.  Smith,  U.  S.  Welding  Co.} 
FIG.  9.— Locomotive  Cylinder  to  be  Welded  in  Place. 


(J)  Lumber  Mills. — Building  up  worn  shafts,  repairing 
gears,  chains,  and  broken  parts. 

(K)  Machine  Shops. — Rectifying  errors  on  part  of  ma- 
chinists and  engineers.  A  "putting-on"  tool  in  every  respect. 

(L)  Manufacturers. — Welding    spouts    and    handles    on 


INTRODUCTION 


13 


cooking  utensils,  fire-proof  doors  arid  window  sashes,  office 
files  and  furniture,  chains,  etc. 

(M)  Mines. — Repairing  pipe  lines,  boilers,  broken  shafts, 
gears,  and  building  up  worn  parts  on  dippers,  etc.  The 
cutting  torch  is  used  for  clearing  away  wreckage  in  case  of 
accidents. 

(N)  Pipe  Work. — Welding  of  water,  gas,  and  oil,  steam 


(Courtesy  of  the  Oxweld  Acetylene  Co.) 

FIG.  io.— Steel  Roll  Top  Desk— all  Joints  and  Seams  Welded.    An  Excellent 
Example  of  High-grade  Welded  Metal  Furniture. 

and  air  lines.  High-pressure  refrigeration  systems  are  cut 
and  welded  in  place. 

(0)  Plate  Welding. — Tanks  for  oil,  steam  driers,  digesters, 
vats,  chemical  receivers,  generators,  etc. 

(P)  Power  Plants. — Welding  of  steam,  air,  and  water-lines, 
of  pump  castings,  cylinders,  pistons,  worn  or  broken  parts,  etc. 

(Q)  Railroad  Work. — Reclaiming  bolsters,  couplings,  slot- 


14  OXY-ACETYLENE  WELDING  MANUAL 

ting  forged  engine  rods,  building  metal  cars,  repairing  fire- 
boxes, patching  and  replacing  side  sheets,  flue  welding,  build- 
ing up  frogs  and  crossings,  cutting  off  rails,  mud  rings,  weld- 
ing cracked  cylinders,  cross-heads,  steam-chests,  building 


(Courtesy  of  the  Oxweld  Acetylene  Co.) 
FIG.  ii.— Office  Chair.     Welded  at  all  Joints. 

up  worn  spots  on  wheels,   rims  and  pins,   welding  spokes 
and  locomotive  frames,  etc. 

(R)  Rolling  Mills. — Fabricating  " open-hearth,"  water 
jacket  doors,  cutting  up  "lost  heats,"  scrap  plates  and  bar 
stock  billets.  General  repairs  of  furnace  equipment,  hot 
beds,  rolls,  gears,  engines,  plates,  etc. 


INTRODUCTION  15 

(S)  Sheet  Metal— Manufacture  of  tubing,  oil-storage 
barrels,  metallic  furniture,  range  boilers,  etc. 

(T)  Shipyards.— Cutting  off  plates  and  irregular  shapes 
of  steel,  channels,  special  sections.  Building  up  of  worn 
shocks,  building  and  patching  hulls,  stringers  and  the  reclama- 
tion of  propellers,  posts  and  broken  parts  of  machinery,  etc. 

(U)  Structural  Steel— Cutting  holes  for  rivets,  gussets  and 
splice  plates,  and  wrecking.  Welding  up  misdrilled  holes 


(Courtesy  of  the  British  Oxygen  Co.) 
FIG.  12. — Cutting  Armor  Plate  by  the  Oxy-acetylene  Process. 

and  machinist's  errors.  Cutting  channels,  I  beams,  and 
other  shapes  for  coping,  splicing  and  fitting  rails,  welding 
reinforcing  rods  for  concrete  work  of  any  desired  length 
and  structural  parts  where  bolting  and  riveting  is  difficult 
or  impossible. 

(V)  Scrap  Yards. — Cutting  up  scrap  boilers,  tanks  and 
other  large  work  to  mill  size,  wrecking  structural  buildings, 
and  reducing  to  small  size,  reservoirs,  tanks  and  boilers, 


16 


OXY-ACETYLENE  WELDING  MANUAL 


which   are  housed   in   buildings   to   remove   them   without 
damage  to  the  structures. 

(W)  Tractor    Industry. — Cutting    and    welding    frames, 
track   and  wheel  guards,   water,   gasoline,   and   oil   tanks; 


1 


(Courtesy  of  the  Davis- Bournonville  Co.) 


FIG.  13. — Here  is  Illustrated  an  Oxy-acetylene  Machine  for  Cutting  Holes 
in  the  Web  of  Rails,  or  in  Structural  Iron,  of  not  more  than  f  Inch  in 
Thickness.  It  can  be  Quickly  Attached  and  Accurately  Adjusted  to 
Pierce  through  the  Iron  Instantly,  without  any  Previous  Drilling,  and 
it  will  Cut  Smooth  Round  Holes,  from  \  to  2  Inches  in  Diameter  in  from 
30  to  60  Seconds.  It  is  Particularly  Adapted  for  Railroad  Work,  and 
Enlarging  or  Cutting  Holes  in  Building  and  Bridge  Work. 


welding  up  of  blowholes,  porous  spots  and  misdrilled  holes 
in  castings  of  all  kinds. 

(13)  The  foregoing,  as  previously  stated,  is  but  a  partial 
list  of  some  of  the  applications  of  the  oxy-acetylene  welding 
and  cutting  process  to  various  industries.  What  has  the 


INTRODUCTION  17 

future  In  store  for  it?  Almost  daily,  some  new  application 
is  found  for  it  and  at  the  present  time  experiments  are  under 
way  in  boiler  construction,  the  results  of  which  are  not  dif- 
ficult to  foresee.  Giant  hulls  of  seagoing  vessels  are  being 
fused  together  by  welding  and  the  limits  of  this  wonderful 
process  which  is  now  practically  in  its  infancy  are  difficult 
to  forecast. 

(14)  During    the   World   War   many   manufacturers    of 
non-essentials   shut   down   and   others    turned    their   entire 
production  over  to  the  government,  changing  their  machinery 
and  in  most  instances  their  entire  plant.    What,  then,  are 
those  who  are  operating  machines  and  apparatus,  produced 
by  these  firms  before  the  war,  going  to  do  for  replacements? 
There  is  but  one  answer,  have  their  broken  or  worn  out 
parts  welded. 

(15)  Oxy-acetylene  operators  have  always  numbered  far 
less  than  the  demand,  a  point  which  was  clearly  brought 
out  by  the  government  when  its  immense  Army  and  Navy 
were  being  formed.    There  were  so  few  men  familiar  with 
the  oxy-acetylene  process  that  it  at  once  took  measures  to 
establish  its  own   schools  where  men  could  be  trained,  a 
thing  that   the   commercial  world   had  been   THINKING  of 
doing  for  some  years.     As  the  demand  for  operators  con- 
tinues to  increase,   it  behooves  a  man,   even    though    he 
is  not  a  metal  worker,  to  think  and  apply  himself,  in  order 
that  he  may  "carry  on,"  to  the  best  advantage  when  oppor- 
tunity knocks. 

(16)  The  methods  of  instruction   herein   set   forth   are 
very  simple  and  while  differing  in  many  respects  from  those 
used  by  the  trade,  have  been  most  successfully  employed 
in  producing  efficient  operators.     Certain  principles  are  in- 
stilled in  the  beginner  and  some  of  the  exceptions  which  are 
of  minor   importance   are   overlooked   to   avoid   confusion. 
Criticism  is  expected  from  those  who  have  never  engaged 


18  OXY-ACETYLENE  WELDING  MANUAL 

in  instruction  of  this  kind  on  a  large  scale.  There  are  many 
differences  to  be  expected  on  account  of  this  very  fact,  for 
there  are  few  who  have  gone  further  than  the  instruction 
of  very  small  classes  where  individual  attention  may  be 
given. 

(17)  All  history  of  the  process,  gas  manufacture  and  the 
like  have  been  omitted  in  order  to  give  greater  detail  to 
the  actual  shop  practice  and  to  have  the  operator  become 
familiar  with  his  apparatus  and  thereby  operate  it  with  all 
due  respect  and  intelligence. 

(18)  Oxy-acetylene  welding  cannot  be  learned  by  watching 
others  work,  although  observation  may  at  times  assist  the 
beginner.     Actual  torch  practice,  brain  work  and  a  power 
of  "I  will,"  produce  the  most  efficient  operators.     For  those 
who  earnestly  apply  themselves  to  the  instructions  which 
follow,  there  is  every  reason  to  believe  that  success  will  be 
theirs. 


CHAPTER  I 
APPARATUS 

(19)  WELDING  apparatus  in  general  consists  of  two  regu- 
lators equipped  with  pressure  gauges,  two  lengths  of  hose, 
and  a  welding  torch.     The  regulators  are  attached  to  cyl- 
inders of  acetylene  and  oxygen  and  are  used  to  reduce  and 
maintain  a  uniform  pressure  of  these  gases  for  use  at  the 
torch.     The  gases  at  reduced  pressure  are  conveyed  to  the 
torch   by   the   hoses.     The   regulators   should   each   have  a 
high-pressure  gauge  to  indicate  the  contents  of  the  cylinder, 
and  also  a  line  or  working-pressure  gauge  to  show  the  gas 
pressure  on  each  hose.     When  the  gases  reach  the  torch  they 
are  there  mixed  and  combustion  takes  place  at  the  welding 
tip,  which  is  fitted  to  the  torch.     Such  an  apparatus  is  called 
portable,   on   account  of  its  movability.     There   are  other 
equipments  wherein  one  or  both  of  the  gases  are  generated, 
but  these  will  not  be  discussed  here. 

(20)  For   convenience   oxy-acetylene   welding   apparatus 
may  be  divided  into  three  classes,  depending  upon  the  prin- 
ciples used  in  securing  the  fuel  gas  or  acetylene  for  the  flame. 
Low-pressure,  medium-pressure  and  high-pressure  apparatus 
generally  use  about  the  same  pressure  of  oxygen  and  it  will 
be  called  a  constant.     The  acetylene  gas  is  a  variable  and 
in  the  low-pressure  type  only  enough  pressure  is  required 
to  overcome  the  friction  of  the  line  until  it  reaches  the  oxy- 
gen injector,  located  in  the  torch,  which  acts  as  a  syphon, 
drawing  the  acetylene  gas  to  the  point  of  ignition.    In  a 
medium-pressure  type  about  three-fourths  as  much  pressure 

19 


20 


OXY-ACETYLENE  WELDING  MANUAL 


is  required  on  the  acetylene  line  as  on  the  oxygen.  This 
type  is  apt  to  verge  on  the  injector  type,  as  it  depends  to 
some  extent  upon  the  oxygen  under  pressure  carrying  acety- 


FIG.  14.— A  Portable  Welding  Unit. 

lene  gas  to  the  point  of  ignition.  In  the  high-pressure  type 
equal  pressure  on  each  line  is  used.  To  further  make  this 
classification  clear,  a  certain  sized  tip  using,  perhaps,  12 


APPARATUS  21 

pounds  of  oxygen  pressure  can  be  used  as  an  example.  In 
a  low-pressure  type  perhaps  2  pounds  pressure  or  less  will 
be  needed  on  the  acetylene  line.  On  the  medium-pressure 
approximately  9  pounds  will  be  required,  while  on  the 
high-pressure  an  equal  amount,  or  12  pounds  will  be  needed. 
(21)  The  mixing  chambers  for  the  gases  may  be  located 
in  the  head;  in  the  middle  of  the  torch,  or  in  the  handle. 
By  mixing  chambers  reference  is  made  to  that  portion  of  the 
torch  where  the  two  gases  are  brought  together  and  mixed. 
As  can  be  seen  with  three  different  types  of  welding  torches 


\te 


FIG.  15. — Location  of  Mixing  Chambers  in  Welding  Torches. 

(i)  Shows  gases  mixing  in  the  handle.  (2)  Has  the  mixing  chamber  in  the  middle  of  the 
torch.  (3)  Illustrates  how  the  gases  are  kept  separate  until  the  head  of  the  torch  is  reached. 
Ox.  represents  oxygen  gas;  Ac.  acetylene  gas;  and  m  mixing  chamber. 

and  three  different  locations  for  the  mixing  of  the  gases, 
the  manufacturers  can  find  a  large  range  for  producing 
oxy-acetylene  apparatus.  Some  undoubtedly  will  fill  cer- 
tain requirements  better  than  others.  Much,  too,'  will  de- 
pend upon  the  ability  of  the  operator  in  handling  a  torch. 
(22)  Flashbacks  are  caused  by  the  improper  mixture  of 
the  gases,  which  increases  the  rate  of  flame  propagation  to 
such  an  extent  that  the  flame  will  flash  back  to  the  mixing 
chamber.  Acetylene  in  a  pure  state  will  burn  very  much 
slower  than  when  mixed  with  equal  parts  of  oxygen.  When 


22  OXY-ACETYLENE  WELDING  MANUAL 

more  oxygen  is  introduced  the  flame  propagation  is  much 
greater,  so  that  when  an  excess  of  oxygen  is  used,  there 
is  bound  to  be  considerable  trouble  from  backflashing.  When 
sufficient  acetylene  is  introduced  to  the  mixing  chamber, 
there  is  absolutely  no  chance  for  this  lean  mixture  to  occur. 
If  the  flame  flashes  back  to  the  mixing  chamber,  both  gases 
should  be  closed  off  immediately,  at  the  torch,  the  oxygen 
first,  and  then  the  acetylene  gas. 

(23)  In  some  torches  the  heating  of  the  mixing  chamber 
will  cause  a  flashback  and  with  these  it  is  necessary  to  shut 
off  the  acetylene  and  leave   the  oxygen  valvs  just  cracked 
and  immerse  the   torch  head   in  water,   dipping  it  slowly, 
so  as  not  to  cause  too  great  a  strain.     The  oxygen  will  bubble 
out  and  prevent  the  water  backing  up  in  the  tip.     If  the 
flashback  deposits  enough  soot  on  the  inside  of  the  tip  and 
the  head  to  impair   the   working  quality  of  the   torch,  the 
soot  should  be  removed  by  using  a  soft  wire,  preferably  of 
copper,  or  some  other  material  which  will  not  mar  the  tip. 

(24)  It  is  interesting  to  note  the  action  of  a  regulator, 
used  to  reduce  the  cylinder  pressure  on  both  gases.     The 
gas  from  the  cy Under,  at  high  pressure,  comes  directly  into 
the  body  of  the  regulator  or  chamber  (4),  Fig.  16,  through 
a  fine  nozzle    (B).      A   seat  of  gallilith,    casenite,    or  fiber 
(C),  attached   to  an  arm   (D),  presses  against   this  nozzle. 
Arm  (D),  in  turn,  is  attached  to  a  very  sensitive  diaphragm 
(E)  and  is  moved  every  time  there  is  a  pressure  exerted  on 
the  latter.     The  movement  of  this  diaphragm  is  controlled 
by  a  handle  or  a  screw,  with  a   " cross-bar"   attached  to 
its  end  as  is  shown  at  (F).     This  screw  bears  upon  the  dia- 
phragm through  the  medium  of  the  springs  (G).    As  this 
screw  is  forced  inward  the  springs  force  the  diaphragm  in, 
and   thereby  move  the  seat  away  from  the  nozzle  of  the 
regulator.     The   gas,   entering   under   high   pressure,   exerts 
an  equal  force  on  all  parts  of  the  chamber  and  the  diaphragm 


APPARATUS 


23 


receives  its  share.  Now  the,  chamber  walls  are  made  of 
a  solid  material,  usually  a  bronze  or  brass,  and  cannot  be 
changed,  but  this  diaphragm  can  be  moved  and  as  this 
pressure  is  increased,  the  diaphragm  is  forced  out  and  the 
nozzle  (B)  is  automatically  closed  by  having  the  seat  (C) 
brought  in  contact  with  it.  When  gas  is  drawn  off  through 
the  line  (H),  the  pressure  within  the  chamber  will  naturally 


FIG.  1 6. — Cross-section  of  Regulator. 

A,  chamber;    B,  nozzle;    C,  seat;    D,  seat  arm;    E,  diaphragm;    F,  cross-bar,  or  adjusting 
screw;  C,  diaphragm  springs;  H,  gas  outlet;  /,  gas  inlet. 

drop  and  as  it  does  so,  the  springs  will  force  the  diaphragm 
inward,  permitting  a  replacement  of  the  gas  drawn  off. 
Although  not  noticeable,  there  is  a  continual  movement  of 
this  diaphragm  whenever  the  gas  is  being  used.  It  can  be 
readily  seen  that  the  amount  of  pressure  within  the  regulator 
can  be  accurately  set  by  the  tension  of  the  spring  against 
the  diaphragm  which  is  controlled  by  the  screw  carrying 
the  "cross-bar." 


24  OXY-ACETYLENE  WELDING  MANUAL 

(25)  There  are  two  types  of  regulators  manufactured  for 
the  reduction  of  gases  under  high  pressure,  depending  upon 
the  nature  of  work  to  be  done.  The  high-pressure  regulator 
is  employed  for  heavy  work  where  a  great  deal  of  gas  is 
used  and  the  regulator  must  pass  it  without  much  effort, 
to  prevent  its  freezing.  This  type  of  regulator  is  used  on 
cutting  or  on  large  welding  work.  It  differs  from  the  low- 
pressure  or  ordinary  type  in  four  distinct  features.  Generally 
it  contains  a  much  heavier  diaphragm  which  is  smaller  in 
diameter,  making  it  stiffer  in  every  respect.  The  tension 
springs  which  act  upon  this  diaphragm  are  much  heavier. 
The  nozzle  which  presses  against  the  seat  is  much  larger, 
to  permit  the  passage  of  a  greater  amount  of  gas.  Then,  too, 
a  larger  working  pressure  gauge  must  be  used,  in  order  to 
read  this  high  pressure.  In  the  welding  of  metals,  especially 
in  steel,  the  adjustment  of  the  flame  is  a  very  important 
matter,  and  absolutely  dependable  regulation  must  be  had. 
This  is  not  possible  with  a  high-pressure  regulator  and  is 
not  intended  to  be  so.  The  larger  the  diaphragm,  the  more 
sensitive  the  regulator,  and  this  point  should  be  borne  in 
mind,  and  no  small  welding  work  attempted  with  the  high- 
pressure  regulator.  The  reverse  form  of  reasoning  may 
be  applied  to  low-pressure  regulators  which  have  been  used 
in  cutting.  They  are  very  likely  to  be  strained  and  satis- 
factory results  cannot  be  expected,  for  they  are  not  made 
for  that  purpose.  Acetylene  regulators  are  constructed  much 
more  sensitively  than  the  oxygen  regulators,  to  take  care 
of  the  lower  pressure  of  gas  and  in  a  sense  might  be  'called 
weaker,  insomuch  that  the  larger  nozzle  which  passes  the 
gas  is  closed  or  regulated  by  springs  which  are  not  nearly 
as  strong  as  in  the  oxygen  regulator.  For  this  reason  acetylene 
regulators  cannot  be  interchanged  with  oxygen  regulators 
for  they  will  not  stand  the  pressure  demanded  in  the  first 
place,  and  in  the  second  place,  were  a  small  quantity  of 


APPARATUS  25 

acetylene  gas  left  in  the  regulator  and  oxygen  introduced, 
an  inflammable  mixture  would  be  formed  which  is  not  ad- 
visable to  have  present,  on  account  of  its  explosiveness. 
In  many  instances  oxygen  regulators  are  put  out  with  the 
copper  diaphragms,  whereas  another  metal  must  be  used 
on  the  acetylene  regulators,  because  acetylene  gas  attacks 
copper  and  usually  a  German  silver  or  rubber  diaphragm 
is  used.  On  account  of  the  lower  pressures  used  in  charging 
the  acetylene  cylinders,  lower  pressure  gauges  are  used 
than  on  oxygen  regulators. 

(26)  All  tension  should  be  removed  from  the  diaphragm 
springs  by  screwing  out  on  the  " cross-bar"  (that  is,  to  the 
left),  before  admitting  gas  under  pressure  to  the  regulator 
to  avoid  abusing  the  seat.  If  a  matter  of  1800  pounds 
pressure  were  admitted  suddenly  into  any  regulator  that 
had  the  seat  removed  from  the  nozzle,  there  would  be  a 
sudden  exertion  upon  the  diaphragm,  which  would  draw  the 
regulator  seat  up  very  violently  against  the  nozzle,  and  if 
it  did  not  crack  the  seat  it  would  undoubtedly  groove  it 
to  such  an  extent  that  it  would  leak  and  a  trouble  known 
as  "creeping  regulator"  would  result.  If  this  occurs,  good 
work  cannot  be  expected  because  the  flame  will  not  remain 
steady,  and  it  is  therefore  necessary  to  take  steps  to  rectify 
this  abuse.  If  there  is  a  welding  company  available,  the 
regulator  should  be  sent  to  it  for  repairs,  but  if  the  operator 
is  in  an  isolated  district  when  this  occurs,  and  must  have 
some  means  of  continuing  work,  it  will  be  possible  for  him 
to  remove  the  seat  by  unscrewing  the  back  of  the  regulator. 
If  the  seat  has  become  grooved,  and  he  thinks  that  this 
is  the  trouble,  many  times  the  seat  can  be  turned  over  and 
the  machined  surface  on  the  other  side  used.  If  the  seat 
is  cracked,  however,  about  the  quickest  way  of  making  an 
emergency  repair  is  to  turn  out  a  new  seat  from  hard  rubber 
ir  fiber  on  a  lathe. 


26  OXY-ACETYLENE  WELDING  MANUAL 

(27)  In  acetylene  cylinders  an  absorbent  called  acetone 
is  generally  used,  which  gives  up  the  gas  as  required.     A 
full  cylinder  can  be  used  for  some  time  without  any  noticeable 
difference  in  the  gauge  reading,  and  then,  as  it  nears  the 
empty  point,  the  gauge  reading  will  drop  very  perceptibly. 
It  is  therefore  impossible  to  depend  upon  a  high-pressure 
acetylene  gauge  as  an  index  to  the  contents  of  the  cylinder. 
The  only  method  known  to  correctly  check  the  amount  of 
acetylene  gas  on  hand  is  to  weigh  the  cylinder.     There  are 
14^  cubic  feet  of  acetylene  gas  to  the  pound,  and  when  the 
net  weight  of  the  cylinder  is  given  the  contents  can  readily 
be  figured.     A  tag  bearing  the  net  weight  or  figures  which 
will  permit  its  computation  is  generally  found  attached  to 
each  acetylene  cylinder.     In  the  case  of  oxygen  cylinders, 
there  being  no  absorbent  used,  the  contents  of  the  cylinder 
is    indicated    on    the    high-pressure    gauge.     On    the    latest 
type  gauge  the  contents  will  be  shown  by  cubic  feet,  by 
pounds  pressure  and  by  atmospheric  pressure,  to  facilitate 
the  computation  of  costs  by  the  operator. 

(28)  Occasionally  a  needle  valve  on  a  torch  will  begin 
to  leak  and  it  will  be  found  necessary  to  grind  it.     Realizing 
that  oil  and  grease  are  not  to  be  used  where  oxygen  is  in 
evidence,  the  question  is  often  brought  up  as  to  the  proper 
lubricant  to  be  used  in  doing  this  kind  of  work.     Glycerine 
is   used    by   most   manufacturers,    together   with   powdered 
glass  or  flour  emery.     In  doing  work  of  this  kind  the  finished 
job   is   thoroughly  washed  with  ether.     Occasionally  when 
piping  oxygen  lines  through  the  shop,  a  screwed  coupling 
will  leak  and  there  is  a  temptation   to   calk  the  same  with 
white  lead,  but  this  should  never  be  done,  rather  use  lead 
oxide  mixed  with  the  glycerine  for  this  purpose  as  it  forms 
a  paste  which  sets  very  rapidly  and  forms  a  hard,  tough 
compound. 


CHAPTER  H 
OPERATION 

(29)  IN  oxy-acetylene  welding  there  are  two  gases  used, 
as  the  name  would  indicate,  namely,  oxygen  and  acetylene. 
The  first  is  used  to  intensify  the  flame  and  can  in  nowise 
be  likened  to  the  inflammable  nature  of  the  second.  There 
is  a  great  deal  of  oxygen  present  in  the  air  we  breathe.  It 
is  an  odorless,  tasteless,  and  colorless  gas,  as  most  of  us  are 
aware.  In  the  commercial  world  oxygen  is  manufactured 
by  the  decomposition  of  water  into  its  elements,  oxygen 
and  hydrogen,  by  the  electrolytic  process  or  is  taken  from 
the  air  by  a  reduction  process  and  is  stored  in  steel-drawn 
cylinders.  These  cylinders  are  drawn  out  of  one  piece  of 
steel  and  are  of  considerable  thickness  throughout,  having 
absolutely  no  seams,  welded  or  otherwise.  There  is  no  filler 
nor  absorbent  used  on  the  inside  of  these  cylinders,  as  pure 
oxygen  under  pressure  is  not  considered  dangerous.  The 
standardized  sized  oxygen  cylinder  is  one  which  contains 
200  cubic  feet  of  gas  fully  charged.  Oxygen  is  compressed 
in  these  cylinders  at  a  pressure  of  1800  pounds,  at  normal 
temperature,  and  this  pressure  does  not  vary  to  any  great 
extent  with  change  in  temperature  (as  shown  by  table  on 
page  29).  There  is  attached  to  the  tip  of  the  steel  cylinder, 
or  "bottle,"  as  some  workers  call  it,  a  double  seating  valve 
which  has  one  seat  operate  when  the  cylinder  is  closed, 
and  the  other  when  the  cylinder  is  wide  open.  A  regulator 
is  attached  to  this  valve  when  working. 

27 


28 


OXY-ACETYLENE  WELDING  MANUAL 


FIG.  17. — Sectional  View  of 
Oxygen  Cylinder  without 
Valve. 


(Courtesy  oj  the  Linde  Air  Products  Co.) 

FIG.  1 8. — A  Standard  2oo-foot  Oxygen 
Cylinder. 


OPERATION 


29 


(30)  Acetylene  is  the  fuel  gas,  and  is  one  of  the  greatest 
containers  of  heat  known.  Burning  in  a  free  state,  its 
carbon  content  is  so  rich  that  complete  combustion  is  im- 

TABLE  SHOWING  THE  DIFFERENT  PRESSURES  OF  OXYGEN— 
AT  VARIOUS  TEMPERATURES 


Temp. 
Deg. 
Fahr. 

Press. 
Lb.  Per 
Deg. 

Temp. 
Deg. 
Fahr. 

Press. 
Lb.  Per 
Deg. 

Temp. 
Deg. 
Fahr. 

Press. 
Lb.  Per 
Deg. 

Temp. 
Deg. 
Fahr. 

Press. 
Lb.  Per 
Deg. 

O 

1568 

25 

i654 

50 

1739 

75 

1824 

I 

1572 

26 

1657 

51 

1743 

76 

1828 

2 

1575 

27 

1660 

52 

1746 

77 

1831 

3 

1579 

28 

1664 

53 

1749 

78 

1835 

4 

1582 

29 

1667 

54 

1753 

79 

1838 

5 

1585 

30 

1671 

55 

1756 

80 

1842 

6 

1589 

31 

1674 

56 

1760 

8! 

1845 

7 

1592 

32 

1678 

57 

1763 

82 

1848 

8 

J596 

33 

1681 

58 

1766 

83 

1852 

9 

1599 

34 

1684 

59 

1770 

84 

1855 

10 

1603 

35 

1688 

60 

1773 

85 

1859 

ii 

1606 

36 

1691 

61 

1777 

86 

1862 

12 

1609 

37 

1695 

62 

1780 

87 

1865 

13 

1613 

38 

1698 

63 

1784 

88 

1869 

14 

1616 

39 

1701 

64 

1787 

89 

1872 

15 

1620 

40 

1705 

65 

1790 

90 

1876 

16 

1623 

4i 

1708 

66 

1794 

9i 

1879 

17 

1626 

42 

1712 

67 

1797 

92 

1883 

18 

1630 

43 

1715 

68 

1800 

93 

1886 

19 

1633 

44 

1719 

69 

1803 

94 

1889 

20 

1637 

45 

1722 

70 

1807 

95 

1893 

21 

1640 

46 

1725 

7i 

1811 

96 

1895 

22 

1643 

47 

1729 

72 

1814 

97 

1900 

23 

1647 

48 

1732 

73 

1818 

98 

1903 

24 

1650 

49 

1736 

74 

1821 

99 

1906 

IOO 

1910 

FIG.  19. 

possible,  and  stringy  black  particles  will  be  noticed  floating 
through  the  air.  In  order  to  fully  combust  this  gas,  oxygen 
is  introduced  under  pressure  and  a  temperature  of  over 


30 


OXY-ACETYLENE  WELDING  MANUAL 


6000  degrees  Fahrenheit  is  obtained.  (Acetylene  contains 
about  five  times  as  many  B.  T.  U.'s  (British  Thermal  Units) 
as  hydrogen.)  This  gas,  unlike  oxygen,  becomes  very  dan- 
gerous when  in  a  free  state  it  is  subjected  to  an  excessive 


FIG.  20.— A  Generator  for  Producing  Acetylene  under  Pressure. 


pressure.  The  slightest  jar  may  cause  its  disintegration 
and  a  violent  explosion  follows.  On  account  of  this 
danger,  acetylene  is  not  stored  in  a  free  state;  neither  is  it 
subjected  to  very  high  pressures.  Its  cylinders  are  put 


OPERATION  31 

out  by  various  manufacturers  to  comply  with  the  laws  and 
regulations  of  the  Interstate  Commerce  Commission.  Some 
of  these  cylinders  have  been  welded,  but  the  most  modern 
method  is  to  make  them  of  one  piece  of  drawn  steel  They 
are  then  filled  with  an  absorbent  of  some  kind  to  take  up 
the  gas  and  prevent  any  portion  of  it  being  left  in  a  free  state. 
Acetone  is  the  popular  absorbent,  and  is  a  liquid  capable 
of  absorbing  twenty-five  times  its  own  volume  of  acetylene 
gas  at  normal  pressure.  The  filling  material  varies  with  each 
of  the  manufacturers,  but  charcoal,  asbestos  and  mineral  wool 
are  in  very  common  use.  Acetylene  is  obtained  from  calcium 
carbide  brought  in  contact  with  water,  or  vice  versa,  and 
is  compressed  and  then  stored  in  the  cylinders  at  a  pressure 
varying  from  150  to  250  pounds.  When  fully  charged 
this  pressure  will  vary  almost  directly  with  any  change 
of  temperature.  Acetylene  cylinders  for  welding  are  avail- 
able in  100,  200,  225,  and  300  cubic  foot  sizes. 

(31)  In  setting  up  apparatus  for  the  first  time,  the  regu- 
lator containing  the  3ooo-pound  gauge  is  attached  to  the 
taller  of  the  cylinders,  which  holds  the  oxygen  gas,  and 
the  other  regulator  is  fastened  to  the  shorter  cylinder.  The 
hoses,  which  should  be  cleared  of  all  powder  or  scale  on 
their  interior,  are  then  added.  The  black  hose  should 
connect  the  oxygen  regulator  to  the  torch  valve,  marked 
"OX"  and  the  red  hose,  the  acetylene  regulator  to  the 
torch  valve  stamped  "AC."  In  attaching  regulators  to 
full  cylinders  the  "cross-bar"  on  the  regulator  should 
always  be  turned  out,  that  is  to  the  left,  until  it  turns  freely, 
to  insure  all  pressure  being  released  from  the  diaphragm, 
before  the  cylinder  pressure  is  turned  on.  Another  pre- 
caution that  should  be  observed  is  the  "cracking"  of  the 
cylinder  valves,  before  attaching  the  regulator,  in  order 
to  blow  out  any  dirt  or  foreign  particles  that  may  be  lodged 
there,  otherwise  they  will  be  carried  into  the  regulator  seat, 


32  OXY-ACETYLENE  WELDING  MANUAL 

or  lodged  in  some  small  passage,  which  will  impair  the 
working  of  the  apparatus.  Then  too,  if  no  truck  or  clamping 
device  has  been  provided,  both  the  oxygen  and  acetylene 
cylinders  should  be  securely  clamped  or  wired  together, 
a  rule  which  should  be  insisted  upon  at  all  times,  whether  in 
a  job  shop,  manufacturing  concern,  or  training  school,  or 
any  place  where  top-heavy  oxygen  cylinders  are  being  used. 
No  particular  harm  results  if  these  cylinders  are  turned  over, 
which  is  very  easily  done  on  account  of  their  rounded  base, 
if  no  regulator  is  attached,  but  very  frequently  regulators 
are  attached  and  the  hose  connecting  the  same  to  torch 
is  found  in  the  operator's  way.  The  slightest  pull  or  tripping 
on  this  hose  will  upset  the  cylinder,  usually  demolishing 
the  regulator  and  expensive  gauges  and  at  times  causing 
much  confusion  among  the  workmen,  on  account  of  the 
loud  hissing  noise  given  off  by  the  escaping  gas.  Always 
secure  the  drums  or  the  cylinders  in  a  safe  manner. 

(32)  In  turning  on  the  gas,  the  oxygen  valve  is  opened 
wide  until  seated  and  the  acetylene  valve  is  only  partially 
opened.     Often  the  question  is  raised  as  to  where  the  oper- 
ator should   stand,  especially  when  dealing  with  high-pres- 
sure oxygen.     It  is  recommended  that  the  operator  should 
stand  at  the  side  and  towards  the  rear  when  performing  this 
operation,   for  sometimes  an  unreliable  gauge  may  be  at- 
tached,  which  if  bursting,   would  send   the  glass  into   the 
operator's  face. 

(33)  As  soon  as  an  operator  has  gas  pressure  in  his  regu- 
lators, he  begins  wondering  how  much  pressure  should  be 
placed  on  his  line,  that  is,  the  portion  between  the  regulator 
and  the  torch.     Of  course,   this  depends  upon  the  size  of 
the  tip,  but  the  operator  should  have  some  means  of  approx- 
imating this  pressure  without  going  to  his  manufacturer's 
chart  every   time.     A  neutral  flame, '  that  is,   theoretically 
equal  parts  of  oxygen  and  acetylene,  is  desired  for  welding. 


OPERATION 


33 


Now  in  lighting,  the  flame  should  stand  away  from  the 
tip  a  slight  distance,  in  torches  other  than  the  low-pressure 
type,  while  in  these  there  will  only  be  a  good  full  flame  issue 
from  the  tip.  Enough  oxygen  must  be  in  evidence  to  bring 
this  acetylene  flame  down  to  the  neutral  point.  If  not 
enough  pressure  is  used,  this  result  cannot  be  obtained, 
and  of  course,  more  pressure  must  be  introduced.  It  is 
better  to  have  too  much  pressure  than  not  enough  on  the 
the  line,  for  the  operator  may  use  his  torch  valve  to  again 
regulate  this  pressure  and  is  always  sure  of  enough  gas. 
Theoretically,  all  adjustments  should  be  made  at  the  regu- 
lator, but  in  practice  this  is  very  seldom  carried  out.  The 
accompanying  cuts  will  illustrate  the  five  conditions  which 
every  welder  should  be  familiar  with,  in  the  flame  adjustment. 
Fig.  21  shows  the  acetylene  turned  on  full;  no  oxygen  has 


FIG.  21. — Acetylene  Flame  Blowing  away  from  Tip. 

as  yet  been  introduced.  The  flame  has  a  yellow  appearance 
and  is  very  rich  in  carbon,  as  can  be  seen  by  the  soot  given 
off.  In  Fig.  22  we  see  the  oxygen  being  turned  on;  the 


FIG.  22. — Addition  of  Oxygen  to  Acetylene  Flame. 

yellow  flame  (A)  is  gradually  giving  way  to  a  white  part 
at  (B).  In  this  condition  we  say  that  a  feather  flame  exists. 
Fig.  23  shows  slightly  more  oxygen  pressure.  In  Fig.  24 
we  have  the  neutral  flame,  which  can  be  readily  recognized 
on  account  of  its  bluish  white  color  and  well-defined  out- 


34 


OXY-ACETYLENE  WELDING  MANUAL 


line,  appearing  like  the  end  of  an  unused  piece  of  chalk, 
only,  of  course,  much  smaller.  In  Fig.  25  can  be  seen  an 
excess  or  too  much  pressure  of  oxygen.  It  will  be  noticed 
that  the  neutral  flame  assumes  a  more  bluish  color,  is  a 


FIG.  23. — More  Oxygen  Pressure  Applied.     Flame  Contains  Slight  Excess  of 
Acetylene,  and  is  Known  as  "Carbonizing." 

little  pointed,  and  a  very  noticeable  hissing  sound  is  in 
evidence.  This  is  what  is  called  an  oxidizing  flame  and  will 
be  again  referred  to.  Too  much  oxygen  is  used.  Operators 
who  attempt  to  turn  on  the  oxygen  first  and  then  light  it, 


FIG.  24.— "Neutral"  Flame.     Correct  Proportions  of  Oxygen  and  Acetylene 

Gases. 

will  find  that  it  does  not  burn,  and  their  efforts  will  be  useless. 
In  picking  up  a  torch  for  the  first  time,  any  operator  can 
turn  on  one  valve  and  detect  by  the  odor  of  the  gas,  whether 
it  is  oxygen  or  the  fuel  gas,  and  can  light  it  in  accordance. 


FIG.  25. — "Oxidizing"  Flame.    Too  much  Oxygen  Present. 

Some  operators,  however,  attempt  to  turn  on  a  little  of 
each  gas  and  light.  This  is  not  to  be  recommended,  for 
flashbacks  may  occur.  When  the  welder  accustoms  himself 
to  turning  on  enough  pressure  to  accommodate  whatever 
sized  tip  he  may  have,  he  will  find  that  there  is  no  great  need 
for  paying  attention  to  the  pressure  gauges  on  his  regulators 


OPERATION  35 

except  to  check  up  on  the  full  drums  of  oxygen,  and  to  teli 
whether  he  has  enough  gas  left  to  complete  a  certain  piece 
of  work. 

(34)  A  neutral  flame  is  theoretically  composed  of  equal 
parts  of  oxygen  and  acetylene  ignited,  but  this  ratio  is  very 
seldom  worked  out  in  practice.     There  is  usually  an  excess 
of  oxygen  in  evidence.     A  neutral  flame  is  generally  spoken 
of  as  being  over  6000  degrees  Fahrenheit,  and  this  does  not 
vary  with  the  different  sized. tips   as  most  welders  think. 
Of  course   there    are   different    quantities  of  heat  between 
a  very  small  tip  and  a  large  sized  one,  but  the  temperature 
of  the  flame  is  the  same. 

(35)  If  too  much  acetylene  gas  is  used,  a  feather  flame 
such  as  was  seen  in  Fig.  23  will  appear.     This  has  a  car- 
bonizing effect  on  the  weld,  for  it  introduces  carbon  and 
causes  the  weld  to  become  very  brittle. 

(36)  If  too  much  oxygen  gas  is  used,  the  effect  shown  in 
Fig.  25  will  take  place,  and  the  weld  will  have  oxygen  intro- 
duced, which  is  a  very  detrimental  feature,  and  is  particu- 
larly noticeable  in  working  on  steel,  for  it  raises  a  white 
foam  over  the  surface  of  the  melted  metal,  which  sometimes 
is  worked  right  into  the  weld  itself/An  experienced  welder 
will  always  know  just  what  kind  of  a  flame  action  he  is 
obtaining  on  his  weld,  not  because  he  takes  the  flame  away 
every  time  he  wishes  to  look  at  it,  but  he  can   tell  by  the 
action  of  his  metal  exactly  the  nature  of  his  flame. 

(37)  Infra-red  (heat)  and  ultra-violet  (light)  rays  present 
to  a  small  extent  in  the  neutral  flame  are  injurious  to  the 
naked  eye.     Colored  glasses  or  goggles   are  used  to   shield 
the  eyes  when  working  with  this  flame.     Too  dark  a  glass 
should  not  be  used,  as  it  will  cause  a  strain  upon  the  eyes 
more  injurious  than  the  flame.    Exposed  metal  frames  should 
be  avoided  too,  as  they  hold  the  heat  and  burn  the  operator. 

(38)  To  shut  off  the .  apparatus  for  several  hours  or  so, 


36 


OXY-ACETYLENE  WELDING  MANUAL 


it  is  best  to  relieve  all  pressure  from  the  lines,  such  as  hose 
and  so  forth,  and  to  do  this  close  both  tank  valves;  open  the 


(Courtesy  of  the  Chicago  Eye  Shield  Co.) 

FIG.  26. — A  Spectacle  Made  for  Welders,  having  a  Frame  of  Fiber  and  Arranged 
so  that  Lenses  may  be  Replaced. 


(Courtesy  of  the  Chicago  Eye  Shield  Co.) 

FIG.  27.— Showing  Cover  Glass  which  Protects  the  Colored  Lens  and  the 
Replaceable  Features  of  a  Modern  Goggle. 

torch  valves;   release  the  tension  on  the  regulator,  by  screw- 
ing the  " cross-bar"  to  the  left,  and  finally,  close  the  torch 


OPERATION  37 

valves.  It  is  quite  necessary  that  these  torch  valves  closed, 
for  quite  frequently,  if  a  small  tip  is  in  the  torch  and 
an  excess  of  oxygen  pressure  comes  through  the  line,  when 
both  torch  valves  are  open,  much  of  the  oxygen  may  back 
up  the  acetylene  line  and  cause  a  serious  flashback  when 
lighting  up.  This  can  be  avoided  by  keeping  both  torch 
valves  closed  when  not  in  use. 

(39)  If  a  valve  on  an  empty  acetylene  cylinder  is  left 
open  the  acetylene  gas  will  escape,  and  mixing  with  the  air, 
which  is  a   supporter   of   combustion,   a  very  inflammable 
mixture  will  be  formed.     If  any  fire  is  present,  such  as  might 
be  smouldering  in   a   forge,   possibly  not  used   for   several 
hours  or  so,  or  a  match  lighted,  or  a  flame  started  in  any 
way,  an  explosion  is  likely  to  occur.     When  an  acetylene 
cylinder  is  exhausted,  as  far  as  possible,  in  a  moderately 
high   atmospheric   temperature,   then   shut  off   for   a  while 
and  the  temperature  drops,  air  will  be  drawn  into  the  vacuum 
thus  formed  when  the  valve  is  again  opened.     In  this  man- 
ner an  explosive  mixture  forms  in  an  empty  acetylene  cylinder 
and   is   certainly   to   be   avoided.     Care   should   be    taken, 
expecially  in  winter,  to  guard  against  such  occurrences,  as 
in  some  outlying  shops  a  decided  change  in   temperature 
takes  place  between  closing  time  and  starting  up  time  the 
following  morning.     Acetylene  tanks  should  always  be  se- 
curely closed  when  empty,   not  only -for  the  above  reasons 
but  insomuch   that  each  contains  acetone,  which  is  likely 
to  escape  if  the  tank  is  thrown  around.     Acetone  is  very 
costly  and  used  extensively  in  the  manufacture  of  smokeless 
powder,  so  that  at  times  it  is  hard  to  replenish. 

(40)  Oxygen  has  an   affinity  for  oils   and  greases,   and 
should  not  be  allowed  to  come  in  contact  with  them,  especially 
in  confined  places,  as  a  spontaneous  combustion  may  result. 
Oils  and  greases  should  never  be  used  around  oxy-acetylene 
welding  apparatus  and  on  nearly  every  apparatus  on  the 


38  OXY-ACETYLENE  WELDING  MANUAL 

market  the  words  "Use  no  oil,"  will  be  found.  Despite  this 
precaution,  however,  many  times  ignorant  operators  will 
be  found  squirting  oil  into  the  holes  around  the  regulator 
cap,  and  through  the  gauges,  in  order,  as  they  say,  to  allow 
them  to  work  easier.  This  use  of  oil  should  be  discouraged, 
and  the  sooner  the  better. 


CHAPTER  III 
SHOP  EQUIPMENT 

(41)  IN  equipping  a  shop  for  welding,  in  addition  to  the 
welding   apparatus,    the   operators   are   many   times   unde- 
cided whether  it  is  advisable  to  have  a  planed  metal  or  a 
brick  top  table  to  use  for  welding  purposes;    each  has  its 
advantages,  but  were  there  a  choice  of  one  or  the  other, 
it  is  suggested  that  the  brick-top  table  be  used.     The  theory 
of  having  a  planed  metal  top  for  lining  up  work  does  not 
prove  as  satisfactory  in  actual  practice  as  might  be  expected, 
for   the   simple   reason   that   the   average   welder   generally 
places  his  metal  in  direct  contact  with  this  cold  top,  and 
much  of  the  heat  which  is  supposed  to  go  into  the  weld  is 
conducted  away  by  the  table  top,  producing  a  hard,  brittle 
weld.     In  the  case  of  cast  iron,  these  welds  are  generally 
porous.     Then  too,  the  operator  to  a  large  extent  depends 
upon  the  table  top  for  lining  up  his  work  and  does  not  study 
his  contraction  and  expansion  as  thoroughly  as  he  might. 
The  result  is  that  many  of  his  pieces  warp  in  cooling.     To 
rectify  the  first  objection  it  is  advisable  to  cover  the  table 
top  with  asbestos  paper  as  shown  in  Fig.  28.     In  the  second 
place,  sometimes  clamps  are  used  to  hold  the  work  in  position. 
Preheating  without    a    layer  of  bricks  on  a  metal-topped 
table  is  not  to  be  recommended. 

(42)  A  fire-brick  table,  made  up  along  the  lines  shown 
in  Fig.  29,  is  very  easily  constructed  and  can  be  used  for  all 
sorts  of  jobs.     It  is  well  to  have  everything  clear  around  the 
legs  and  have  no  braces  to  cut  the  operator  on  the  shins 

39 


40 


OXY-ACETYLENE  WELDING  MANUAL 


or  to  interfere  in  any  way  with  his  work.     The  best  fire 
bricks  obtainable  should  be  used.     A  large  number  of  extra 


FIG.  28.— Method  of  Holding  Heat  when  Welding  on  Metal  Top  Tables. 

Asbestos  paper,  P,  is  laid  upon  the  metal  top,  M,  and  the  pieces,  A  and  B,  placed  upon  P 
in  such  a  manner  that  the  weld  can  be  made  at  C.  The  asbestos  paper  prevents  too  much  heat 
escaping  from  the  bottom  of  the  weld. 

bricks  should  always  be   on  hand  for  they  come  in  very 
handy  in  most  of  the  welding  operations,  and  in  fact  to 


FIG.  29.— A  Fire-brick  Table  for  Welding. 

Angle  iron  measuring  2  by  2  by  \  inches  is  welded  together  in  the  manner  shown  and  covered 
with  fire-bricks  which  measure  2  i  by  45  by  9  inches. 

conduct  a  welding  shop  without  fire  bricks  could  almost 
be  likened  to  a  blacksmith's  shop  without  an  anvil.  Be- 
sides being  used  for  table  tops,  preheating  furnaces  of  a 


SHOP  EQUIPMENT 


41 


temporary  nature  may  be  built  and  the  bricks  used  to  jack 
up  and  align  many  jobs  which  could  not  be  handled  otherwise. 
(43)  An  emery  wheel  plays  a  very  important  part  in  a 
commercial  welding  shop,  insomuch  that  rust,  scale,  and 
unnecessary  metal  can  be  removed  in  a  very  short  time 
by  its  use.  A  flexible  shaft  attachment  should  be  on  hand, 


FIG.  30. — One  Shop  in  which  Instruction  in  Steel  is  being  Given,  at  the 

Ordnance  Welding  School. 

Note  the  construction  of  the  welding  tables.    Two  or  more  may  be  placed  together,  to  give 
as  large  a  surface  as  desired. 

if  possible,  or  a  portable  grinder  of  some  kind,  for  in  many 
cases  where  the  casting,  or  the  piece  being  worked  upon  is 
too  heavy  to  bring  to  the  emery  wheel,  the  wheel  can  be 
brought  to  it  and  many  places  ground  down  by  its  use  that 
would  be  impossible  with  a  stationary  grinder. 

(44)  Many  times  when  working  near  a  hole  which  may 
be  threaded,  the  welder  has  much  difficulty  in  keeping  his 


42  OXY-ACETYLENE  WELDING  MANUAL 

metal  from  entering  the  hole.  At  other  times  it  is  neces- 
sary to  back  up  preheated  work  such  as  aluminum,  to 
prevent  its  collapsing.  Ordinary  clay  or  putty  cannot 
be  used  for  this  purpose.  The  simple  reason  being  that 
when  metal  is  heated  it  expands  and  the  clay  or  putty  in 
giving  off  its  moisture  contracts,  showing  two  opposite  reac- 
tions. Retort  cement  is  a  name  given  furnace  cement 
mixed  with  shredded  asbestos,  this,  as  well  as  carbon  flour, 
has  been  found  to  be  very  satisfactory  for  filling  in  holes 
and  backing  up  pre-heated  work.  Retort  cement  is  purchased 
in  airtight  containers,  hardening  very  quickly  when  brought 
in  contact  with  the  air,  so  at  all  times  it  should  be  kept  in 
containers  similar  to  those  in  which  it  is  purchased.  It 
cannot  be  reclaimed  once  it  is  hardened. 

(45)  A  blacksmith  forge  will  be   the  medium  of  saving 
much  valuable  gas  and  time  in  a  welding  shop.     It  will  heat 
up  parts  to  be  welded  in  very  short  order  and  while  in  this 
condition  they  may  be  welded  and  then  thrown  back  into 
the  forge  and  allowed  to  cool  very  slowly. 

(46)  Several  pails  of    water  should    always    be    located 
where   welding  is  being   done   to   prevent   fire   from   flying 
sparks;    to  cool  the  torch  tips  and  filler-rods,  when  working 
on  large  jobs;    to  keep  certain  parts  of  work  being  welded 
cool,  and  to  harden  or  temper  other  parts.    . 

(47)  A  simple  and  efficient  manner  of  handling  flux  in 
the  welding   shop  has  puzzled  many  welders,   on   account 
of  the  flux  containers  being  easily  upset,  their  inaccesibility 
and  the  action  of  the  air  upon  large  quantities  of  flux.    A 
simple  method  of  overcoming  this  is   to   cut  in  two,  a  two 
and  one-half  or   three-inch  pipe  coupling  and  mount  it  by 
welding  on  a  square  piece  of  one-eighth  inch  plate,  as  shown  in 
Fig.   31.     This  type  of    container    is  very  hard    to    upset* 
may  be  used  when  working  on  preheated  jobs;  is  easy  to  get 
at  on  account  of  its  shallow  nature,  and,  as  it  only  holds •  a 


SHOP  EQUIPMENT 


43 


small  amount  of  flux,  it  can  be  cleaned  out  frequently  and 
a  fresh  flux  will  always  be  available. 

(48)  Additional  equipment  beneficial  to  the  welder  will 
be  a  quantity  of  various  sized  carbon  rods  and  blocks;    as- 
bestos paper;    goggles;    V-blocks  for  lining  up  shafts  and 
an  assortment  of  mechanics'  tools,  such  as  wrenches,  ham- 
mers, chisels,  hack-saws,  and  other  things  which  might  be 
used  in  dissembling  or  assembling  various  kinds  of  machinery. 

(49)  Another  important  item  which  is  generally  overlooked 
in  the  average  welding  shop  is  the  question  of  ventilation. 
Although  the  welding  flame  itself  contains  no  objectionable 


FIG.  31.— A  Good  Flux  Container  for  the  Welding  Table. 

gases,  those  from  fresh  charcoal  preheating  fires,  those  given 
off  when  some  of  the  alloys  of  the  filler-rods  are  melted 
when  brass,  copper,  and  other  metals  are  being  worked  on, 
and  from  gas  engine  exhausts  are  not  desirable.  At  times 
they  will  give  the  operators  violent  headaches  unless  means 
are  taken  to  carry  them  off.  The  ventilation  should  be  such 
that  it  will  not  directly  affect  the  work.  Drafts  are  to 
be  avoided  as  much  as  possible,  for  many  times  they  will 
warp  pieces  being  preheated  if  allowed  to  come  in  direct 
contact  with  them.  It  is  a  good  thing  to  remember  that 
indirect  ventilation  and  plenty  of  it  is  a  prime  requisite 
in  a  good  welding  shop. 


CHAPTER  IV 
APPARATUS  REPAIRS 

(50)  OCCASIONALLY  in  setting  up  a  welding  apparatus,  a 
leak  may  be  noticed  along  the  lines,  some  time  after  the 
plant  is  in  operation.     Leaks  on  either  the  oxygen  or  acet- 
ylene lines  are  to  be  considered  dangerous  as  well  as  costly 
and  therefore  to  be  avoided  at  all  times.     When  the  cylinder 
valves  are  closed  on  the  drums  containing  the  gases,  and  the 
hands   on   the   low-pressure   gauges   of   each   regulator   are 
seen  to  drop  or  reduce  their  pressure  when  the  torch  valves 
are  shut  off  and  allowed  to  remain  so,  this  is  an  indication 
that  there  is  a  leak  between  the  regulator  and  the  torch. 
It  is  not  desirable  to  use  a  match  or  a  flame  of  any  kind 
in  testing  for  leaks.     There  are  various  methods  employed 
by  the  cautious  welder,  but  about  the  best  of  these  is  a  soapy 
solution  of  water,  which  is  kept  in  a  can  at  all  times  and 
is  applied  with  a  paint  brush.     If  this  solution  is  applied  to 
any   leaky   part,   bubbles   will   form   immediately   and   the 
leak  will  bt  located. 

(51)  At    times,  when  working  in  isolated  places,   where 
repairs    cannot    be    had,    and   no    means   have    previously 
presented  themselves  for   testing  out  the  cylinders  or   the 
apparatus  as  a-  whole,  it  may  be  found  that  the  threads  or 
ground  seat  on  the  cylinder  valve  of  the  regulator  which 
is  connected  will  be  in  such  a  condition  that  a  leak  is  in  evi- 
dence.    Or  it  may  be  that  the  threads  will  not  permit  the 
seat  being   drawn   up    sufficiently  to  make  it  airtight.     In 
cases  of  this  kind,  the  welder  must  find  some  means  of  pro- 

44 


APPARATUS  REPAIRS  45 

ceeding  with  his  work,  and  while  it  will  be  impossible  for 
him  to  use  white  lead  or  any  oily  substance  with  safety, 
he  may  stop  the  leak  with  litharge  or  lead  oxide  mixed  with 
a  small  quantity  of  glycerine.  A  string  soaked  in  this  solution 
may  be  wound  around  the  main  connection  and  the  swivel 
nut  screwed  up  to  the  seat  as  far  as  it  will  go.  If  allowed 
to  harden  for  a  short  time,  the  litharge  will  set  and  a  very 
satisfactory  temporary  repair  will  be  effected. 

(52)  The  method  shown  in  Fig.  32  of  attaching  con- 
nections to  hoses  so  that  they  will  not  blow  off  when  pres- 
sure is  applied  is  a  very  simple  and  effective  means  of  over- 
coming this  difficulty.  Undoubtedly  it  will  assist  some 
operators  in  solving  the  trouble  that  has  been  occasioned  by 


FIG.  32. — Method  of  Attaching  Hose  to  Connection  so  it  cannot  Pull  or  Blow  off. 

the  ordinary  hose  clamps,  especially  when  doing  cutting  or 
heavy  welding  work  where  the  gas  pressure  is  considerably 
higher  than  usual.  The  wire  used  should  be  large  enough  to 
prevent  cutting  the  fabric  in  the  hose. 

(53)  An  injured  hose  which  may  leak  should  never  be 
used  after  the  leak  is  noticed  unless  some  means  are  taken 
to  repair  it.  The  use  of  tape  in  trying  to  repair  hose  on 
an  oxy-acetylene  welding  outfit  should  never  be  permitted. 
The  most  efficient  way  of  overcoming  an  injury  of  this  kind 
is  to  cut  the  hose  at  this  part  and  insert  a  piece  of  pipe. 
The  ends  of  the  hose  are  then  wired  to  this  pipe  and  a  union 
is  thereby  effected  which  will  generally  outlast  the  life  of 
the  hose.  Special  connections  for  this  purpose  are  put  out 
by  most  welding  companies,  so  that  a  supply  may  be  on 
hand  if  hose  trouble  is  expected. 


46  OXY-ACETYLENE  WELDING  MANUAL 

(54)  When  transporting  welding  apparatus,  occasionally 
the  " cross-bar"  on  the  regulator  is  lost  and  many  times  the 
operators  do  not  know  what  is  to  be  done.     The  purpose 
of  the  "  cross-bar,"  as  we  have  already  seen,  is  only  to  apply 
pressure  on  the  diaphragm  springs,  so  that  if  a  set  screw 
of  the  same  diameter  and  same  thread  as  those  of  the  "  cross- 
bar" can  be  found  and  screwed  into  its  place  with  a  wrench, 
a  section  of  filler-rod  can  be  welded  across  the  top  of  it  and 
the  use  of  the  regulator  will  not  be  impaired.     If  a  special 
thread  is  used  by  any  particular  company,  a  piece  of  brass 
or  iron  can  be  turned  down  in  a  lathe  to  fit. 

(55)  The  manufacturers  of  practically  all  regulators  use 
the  quarter-inch  tapered  pipe  thread  in  attaching  the  cylinder 
connections  to  the  regulator  and  do  not  depend  upon  the 
threads  being  gas-tight,  so  they  solder  them  in.     There  are 
various  types  of  cylinder  connections  put  out  by  different 
manufacturers  of  the  gases  and  occasionally  it  may  be  neces- 
sary to  use  a  cylinder  of  gas  which  contains  a  different  con- 
nection than  is  supplied  on  the  regulator.     Various  adapters, 
such  as  shown  in  Fig.  33,  are   supplied   to   overcome  this 
difficulty,  but  at  times  the  operator  is  confronted   with  the 
very  embarrassing   situation,  of  having    a    cylinder   of   gas 
and  his  regulator  of  different  connections,  but  no  adapter 
suitable.     This   predicament   is   usually   found    when    some 
very  important  work  is  to  be  done  and  sometimes  far  from 
a  supply  depot.     At  times  the  operator  may  have  an  adapter 
which  will  fit  the  cylinder  but  not  the  regulator.     If  this  is 
the  case,  his  difficulty  can  be  very  easily  overcome,  for  gen- 
erally all  adapters  are  made  of  two  parts,  " sweated"  to- 
gether, and  have  the  same  quarter- inch  tapered  thread  as 
used  in  the  cylinder  connections  on  the  regulator.     The  adapter 
can  be  separated,   the   tank   connection   removed  and    the 
correct  connection  " sweated"  into  the  regulator. 

(56)  Most  gauges  used  in  the  oxy-acetylene  industry  to 


APPARATUS  REPAIRS  47 

indicate  gas  pressure  are  of  the  Bourbon  type.  The  most 
recent  types  of  the  oxygen  high-pressure  gauges  are  con- 
structed with  a  hinged  back  and  a  solid  front,  which  means 
that  should  an  oil  or  foreign  matter  enter  the  gauge  from 


(Courtesy  of  the  Bastian- Blessing  Co.) 

FIG.  33. — Various  Types  of  Adaptors  Used  to  Connect  Regulators  to  Cyl- 
inders having  Different  Connection. 

any  source  whatsoever  and  tend  to  burst  it,  the  back  would 
be  blown  off  and  there  would  be  no  glass  that  could  possibly 
fly  around.  This  is  a  safety  device  which  has  been  welcomed 
with  much  enthusiasm  on  the  part  of  the  oxy-acetylene  in- 


48 


OXY-ACETYLENE  WELDING  MANUAL 


dustry.  When  leaks  occur  in  gauges,  it  is  always  best  to 
remove  the  guage  from  the  regulator,  stopping  the  hole 
temporarily  with  a  pipe  plug  and  return  the  gauge  to  the 
manufacturers  for  repair.  These  gauges  are  very  delicately 
constructed  and  can  be  rendered  useless  if  handled  by  the 


(Courtesy  of  the  U.  S.  Gauge  Co.) 

FIG,  34. — Showing  Solid-front  and  Hinged-back  Features  of  a  "Safety-first" 
High-pressure  Oxygen  Gauge. 

inexperienced.  A  great  many  times  after  the  case  of  the 
gauge  has  been  jarred  or  loosened,  the  screws  connecting 
this  case  to  the  inside  working  mechanism  are  tightened  up, 
breaking  the  soldered  connection  holding  the  spring  tube 
on  the  inside  of  the  gauge.  This  causes  a  leak  which  can 


APPARATUS  REPAIRS 


49 


be  repaired  quite  easily  if  the  operator  is  able  to  solder  it. 
It  must  be  remembered,  however,  that  if  the  flame  is  brought 
in  contact  with  any  of  the  springs  that  their  tension  will  be 
lost  and  that  the  gauge  may  not  operate  correctlv  after  this 
repair  is  made  unless  great  care  is  exercised. 

(57)  Undoubtedly  there  are  many  welders  who  in  begin- 
ning to  operate  their  welding  apparatus  conclude  that  their 


FIG.  35.— A  3ooo-pound  High-pressure  Oxygen  Gauge. 

gauges  must  be  at  fault  when  they  show  a  reading  after 
apparently  all  pressure  has  been  released  in  closing  down  the 
apparatus.  It  is  to  avoid  the  impression  that  the  gauge 
is  at  fault  that  time  is  here  taken  to  show  that  even  though 
the  cylinder  valve  is  closed  and  the  "  cross-bar  "  on  the  regu- 
lator screwed  out  that  when  the  torch  valves  are  opened  to 
drain  the  lines  there  will  still  be  a  reading  on  the  high-pressure 


50  OXY-ACETYLENE  WELDING  MANUAL 

gauge  if  the  regulator  seat  is  in  good  working  order.  It  is 
simply  a  case  of  gas  being  trapped  between  the  regulator 
and  the  cylinder  valve.  To  reduce  this  reading  it  is  only 
necessary  to  screw  in  the  "  cross-bar,"  thus  opening  the 
regulator  seat.  This  could  be  avoided  if  the  cylinder  valve 
were  closed  first  and  the  torch  valves  opened  while  the  regu- 
lator "  cross-bar  "  were  still  screwed  in,  then  as  soon  as  the 
gas  had  left  the  line,  the  torch  valves  could  be  closed  and 
the  "  cross-bar "  on  the  regulator  could  be  screwed  out 
until  free. 


CHAPTER  V 
PREHEATING  AGENCIES 

(58)  PREHEATING,  as  applied  to  oxy-acetylene  welding, 
means  the  application  of   heat  to  the  article  to  be  welded 


(Courtesy  of  the  Messer  Mfg.  Co.) 
FIG.  36. — A  Large  Job  Prepared  for  Welding. 

in  some  manner  which  is  usually  different  than  by  the 
welding  flame  itself.  Charcoal,  coke,  kerosene,  crude  oil, 
coal  and  natural  gas  are  used  for  this  purpose.  The  prin- 
cipal reasons  for  pre-heating  parts  to  be  welded  are:  To 
take  care  of  the  effects  of  contraction  and  expansion  on  the 
confined  ends;  to  save  time,  gas,  and  material;  and  to  make 

51 


52  OXY-ACETYLENE  WELDING  MANUAL 

a  better  weld  by  making  it  quicker  and  with  less  chance  of 
burning  up  the  metal. 

(59)  On  account  of  the  ductile  qualities  of  steel,  there 
is  not  quite  as  much  heat  used  in  preheating,  to  take  care 
of  the  contraction  and  expansion,  as  in  cast  iron.  On  brass 
work  a  very  dull  red  heat  is  considered  sufficient,  or  other- 
wise the  alloys  might  burn  out.  When  preheating  aluminum, 


(Courtesy  oj  the  Messer  Mfg.  Co.) 

FIG.  37. — Showing  how  Large  Work  can  be  Covered  with  Asbestos  Paper 
when  Preheating. 

there  will  be  no  change  in  color  as  the  heat  is  introduced, 
so  other  methods  are  used  to  determine  the  correct  tem- 
perature. Three  methods  are  used  for  this  purpose  by  most 
welders.  "  Half-and-half "  soldering  wire  will  usually 
melt  when  applied  to  the  surface  of  aluminum  which  is 
preheated  to  the  proper  state;  the  puddle  stick  when  drawn 
smartly  across  the  heated  surface  should  scrape  off  the 
oxide  and  leave  a  clear  blue  streak  if  the  work  is  in  condition 


PREHEATING  AGENCIES  53 

to  be  welded;  and  if  a  medium-sized  tip  is  brought  down  so 
that  the  neutral  flame  just  touches  the  surface  for  a  second 
or  two,  the  metal  will  sweat,  if  at  the  proper  temperature, 
and  small  globules  which  have  the  appearance  of  mercury 
will  stand  out  on  the  surface. 

(60)  The  beginner  must  study  contraction  and  expansion 
in  order  that  he  may  know  when  and  where  to  apply  it  in 
figuring   out   his  work.     Many  welding  jobs    have    turned 
out  to  be  failures  through  lack  of  knowledge  in  this  respect. 
Take,  for  example,  a  water-cooled  cylinder  block  of  the  ordi- 
nary gas  engine;   the  water-jacket  may  be  broken  when  the 
water  is  allowed  to  freeze  in  it.     This  problem  has  certainly 
confined  ends,  but  some  welders  have  attempted  to  weld  such 
jobs  cold,  that  is,  without  preheating,  and  possibly  have 
succeeded  in  executing  what  they  thought  was  a  very  fine 
weld,  but  upon  examination,  have  discovered  that  the  cylinder 
walls,  which  are  very  accurately  machined,  have  been  warped 
to  such  an  extent  that  the  block  is  rendered  useless.     This 
is  strictly  a  "  preheating  "  job,  and  the  cylinder  should  be 
brought  to  a  dull  red  heat  if  the  best  results  are  to  follow.    • 

As  has  been  stated  elsewhere  in  this  volume,  the  weld 
should  not  be  considered  successful  unless  the  piece  worked 
upon  can  be  returned  to  a  usable  state. 

(61)  Several    different    fuels    have    been  mentioned,   all 
of  which   can  be  used  for  preheating  purposes.     Charcoal 
is  considered  the  best  agent  for  general  welding,  as  it  gives  off 
a  very  steady  heat  which  will  gradually  be  absorbed  by  the 
article  worked  upon,  bringing  it  to  the  heat  desired  and  hold- 
ing it  there  throughout  the  welding  operation.     It  will   then 
permit  very  gradual  cooling,  as  this  sort  of  fire  takes  a  long 
time  in  dying — a  desirable  asset  in  work  of  this  kind.     On 
account  of  the  scarcity  of  charcoal  and  its  high  price,  other 
agencies  are  used  and  chief  among  them  are  torches  using 
kerosene,  crude  oil,  or  city  gas,  as  a  fuel.    These  usually 


54 


OXY-ACETYLENE  WELDING  MANUAL 


heat  up  the  work  more  quickly,  but  care  in  their  manipula- 
tion is  necessary.  A  preheating  torch  to  be  used  in  con- 
junction with  city  gas  can  be  very  easily  constructed,  if  the 
details  of  Fig.  38  are  observed.  This  proves  to  be  a  very 
efficient  and  cheaply  constructed  apparatus. 


FIG.  38. — Preheating  Torch,  Constructed  of  Black  Iron  Pipe,  for  Burning 

City  Gas. 

(62)  When  work  is  being  preheated,  it  is  best  to  have 
it  protected  from  all  drafts,  to  prevent  warping.  Possibly 
the  most  extensively  used  material  for  building  up  temporary 
ovens  to  hold  the  heat  and  protect  the  work  from  the  air 
currents  is  fire  brick  and  with  it  asbestos  paper.  When 


FIG.  39. — Temporary  Preheating  Oven,  Built  of  Fire  Brick. 

setting  up  an  ordinary  casting  for  preheating,  these  bricks 
are  built  up  in  builder's  fashion,  about  four  inches  away  from 
the  piece  itself,  as  shown  in  Fig.  39,  and  practically  level 
with  the  top  of  the  piece.  If  charcoal  is  to  be  used,  draft 
spaces  are  left  in  the  first  row  of  bricks  as  shown,  and  the 
charcoal  ignited  through  the  openings  with  the  welding 
torch.  The  work  to  be  welded  should  have  the  line  of  weld 
at  the  top  if  possible  and  be  set  up  from  the  floor,  or  the  sur- 


PREHEATING  AGENCIES  55 

face  upon  which  the  oven  is  resting,  on  one  or  two  fire  bricks, 
in  order  that  the  full  benefit  of  the  heat  will  be  received. 
Asbestos  paper  is  then  laid  across  the  top,  and  the  oven  will 
appear  as  in  Fig.  40.  When  starting  the  fire,  a  layer  of 
charcoal,  a  matter  of  two  or  three  inches  thick,  is  at  first 
used,  but  as  the  chill  is  taken  off  the  piece  the  oven  can  be 
filled  to  the  top,  and  usually  this  is  enough  to  complete  the 
work. 

(63)  In  order  to  protect  the  operator,  when  working  over 
hot  fires,  it  is  recommended  that  the  asbestos  covering  be 
left  on,  and  that  only  a  small  section  immediately  in  the 


FIG.  40. — Temporary  Preheating  Oven  of  Fire  Bricks  Covered  with  Asbestos 

Paper. 

vicinity  of  the  weld  be  removed,  which  can  be  accomplished 
by  cutting  a  "  U  "  in  the  paper  as  shown  by  the  dotted  lines 
in  Fig.  40.  This  can  be  turned  back,  exposing  the  place 
which  is  to  be  welded,  and  at  the  same  time  protecting  the 
operator,  to  a  large  extent,  from  the  unnecessary  heat. 
When  the  weld  is  finished,  this  lap  can  be  turned  back  and 
the  piece  allowed  to  cool.  On  pieces  which  require  turning 
and  must  be  welded  in  several  different  positions,  the  pre- 
heating oven,  as  it  is  called,  should  be  built  considerably 
larger,  to  provide  for  handling  the  work.  ,  It  must  be  remem- 
bered that  during  the  entire  operation,  the  piece  should  be 
left  inside  the  oven  and  should  not  be  removed  to  a  welding 


56 


OXY-ACETYLENE  WELDING  MANUAL 


table.  Some  beginners  make  the  mistake  of  doing  this. 
When  welding  with  the  charcoal  in  closed  rooms,  during  the 
winter  months,  the  fumes  will  be  found  to  be  very  disagree- 
able and  means  should  be  taken  to  provide  indirect  ventila- 
tion, otherwise  the  welders  will  be  troubled  with  headaches 
and  smarting  eyes. 

(64)  When  using  preheating  torches,  the  ovens  are  built 
much  closer  to  the  work  and  do  not  have  the  openings  along 
the  bottom  row  of  bricks.  They  are  made  as  tight  as  possible, 
and  in  some  cases  it  will  be  found  advisable  to  build  up  the 
walls  with  two  layers  of  bricks,  with  asbestos  paper  between 


FIG.  41. — Showing  How  Oven  is  Built  when  Preheating  Torch  is  to  be  Used. 
Torch  is  Showi..  at  (A). 

them,  in  order  to  hold  the  heat  and  cause  the  work  to  heat 
up  in  a  more  uniform  manner.  A  hole  is  left  in  one  end  of 
the  oven,  through  which  the  flame  of  the  preheating  torch 
is  introduced  as  shown  in  Fig.  41.  It  is  not  thought  best 
to  have  the  torch  flame  come  in  direct  contact  with  the  work 
which  is  being  preheated,  and  a  baffling  plate  of  metal  or 
brick  is  placed  directly  in  front  of  the  flame,  in  order  to 
spread  it  around  the  oven.  Judgment  will  have  to  be  used 
in  all  such  work. 

(65)  The  setting  up  of  the  work,  when  preheating,  is  an 
important  point  overlooked  by  many  welders,  especially  so 
in  the  case  of  aluminum.  Care  should  be  taken  to  see  that  the 


PREHEATING  AGENCIES  57 

work  has  a  good  solid  setting  and  is  braced  at  a  sufficient 
number  of  points,  to  prevent  its  sagging  when  in  a  pre- 
heated condition.  Many  times  when  working  on  rough  sur- 
faces, a  few  firebricks  distributed  around  the  bottom  of  the 
oven  with  a  dab  of  putty,  clay,  or  retort  cement,  placed  upon 
them,  will  form  an  excellent  cushion  upon  which  the  work 
can  rest  and  the  operator  may  feel  confident  that  no  sagging 
will  occur. 


CHAPTER  VI 
PART  ONE.— WELDING  OF  CAST  IRON 

(66)  IN  order  to  know  how  to  weld,  it  is  quite  imperative 
that  the  operator  first  know  the  kind  of  metal  he  is  to  work 
on.     It  is  surprising  to  find  how  few  welders    know  their 
metals  thoroughly.     An  incident  might  be  cited  where  some 
welders  depend  upon   the  sparks  given  off  by   the   emery 
wheel  in  determining  the  kind  of  metal  they  are  about  to 
weld.     They  will  approach  the  wheel;   grind  off  their   work, 
noting  the  sparks;  return  to  their  welding  table;  choose  their 
filler- rods  and  do  their  welding  without  any  delay  whatso- 
ever,  much   to   the   consternation  of    their   fellow  workers. 
There  are  four  simple  ways  in   common  use  to  distinguish 
between  cast  iron,  malleable  iron,  and  steel;  they  are:    By 
the  cross-section  of  a  fresh  break,  by  application  of  the  weld- 
ing torch,  by  the  sparks  given  off  when  applied  to  the  emery 
wheel  and  by  the  chisel  test. 

(67)  Externally  cast  iron  usually  has  some  sand  on  its 
surface  and  its  cross-section  shows  the  grain  to  t>e  fine,  even, 
and  to  have  a  dull  grayish  color.     The  surface  of  malleable 
iron  contains  no  sand  and  its  grain  is  very  fine,  such  as  cast 
iron,  but  slightly  darker  in  color.     A  very  fine  steel  veneer 
is  on  all  surfaces  of  malleable  iron,  which  is  much  lighter 
in  color.     When  the  welding  torch  is  applied  to  cast  iron, 
no  sparks  are  given  off,  but  when  applied  to  malleable  iron  a 
bright  spark  is  thrown  off  which  breaks  in  falling,  showing 
that  the  outside  material  is  steel.     These  sparks  soon  cease 
and  the  metal  which  is  molten  is  covered  by  a  heavy  oxide 

58 


WELDING  OF   CAST  IRON 


59 


or  skin  which  recedes  or  draws  away  from  the  flame  slightly, 
showing  a  very  porous  cast-iron  interior.     When  brought  in 


FIG.  42. — Characteristic  Sparks  of  Different  Irons  and  Steels  Thrown  off 
by  an  Emery  Wheel.  Wheel  should  be  Clean  Cutting  and  Run  about 
7000  Feet  per  Minute. 

(1)  Shows  cast  iron.     No  sparks  unless  impurities  arc  present. 

(2)  Is  wrought  iron  almost  free  from  carbon.     Heated  particles  thrown  from  wheel  follow 
straight  line.     These  become  broader  and  more  luminous  some  distance  from  their  source  of  heat. 

(3)  Illustrates  mild  steel  action.     Small  amount  of  carbon  present  causes  a  division  or  forking 
of  the  luminous  streak. 

(4)  Shows  the  effect  of  increasing  the  carbon  from  0.50  to  0.85  per  cent  in  mild  steel.     The 
iron  spark  lines  diminish:   the  forking  of   the   luminous   Ftreak   occurs   more   frequently,   being 
subdivided  by  re-explosions  from  smaller  particles. 

(5)  Is  a  piece  of  carbon  tool  steel.     The  iron  lines  are  practically  eliminated  with  the  increase 
of  the  explosions  and  subdivisions,  causing  display  of  figures. 

(6)  Gives  the  spark  of  high-speed  steel,   containing  in  addition  to  65  per  cent  carbon,  other 
alloying  elements,  chiefly  tungsten  and  chromium. 

(7)  Represents  a  manganese  spark.     (Occasionally  found  in  cast  iron.) 

(8)  Shows  spark  thrown  from  old  grade  of  "Mushett"  steel. 

(9)  Represents  a  magnet  steel  spark. 

contact  with  the  emery  wheel  steel  sparks,  which  are  very 
luminous  and  break  in  falling,  are  given  off  first  in  the  case  of 
malleable  iron,  but  they  soon  change  to  the  dull  red  spark 


60 


OXY-ACETYLENE  WELDING  MANUAL 


of  cast  iron.  When  a  chisel  is  applied  to  cast  iron,  the  iron 
chips  off;  when  applied  to  malleable  iron  the  edge  will  curl 
up,  then  chip  off  when  the  cast  iron  is  reached.  The  cross- 
section  of  cast  steel  shows  a  bright,  coarse,  silvery  gray 

METHODS  OF  DISTINGUISHING  METALS 

Here  are  five  methods,  any  one  or  all  of  which  may  be  used  to  learn  the 
nature  of  common  castings  which  might  confuse  the  welder. 


No. 

I 

Test. 

Malleable  Iron. 

Cast  Steel. 

Cast  Iron. 

Outside 
Appear- 
ance 

Generally  smooth  and 
free  from  all  sand, 
weighs  about  same 
as  cast  iron. 

Rough  surface 
with  sand  in  evi- 
dence, weighs 
much  more 
than  cast  iron. 

Surface  fairly 
smooth  but  gen- 
erally shows 
some  sand. 

2 

Cross- 
section 
Test 

Ring  of  bright  steel 
crystals  outside, 
with  darker  iron 
crystals  inside. 

Large,  bright, 
luminous,  sil- 
ver crystals. 

Fine,  uniform, 
dark  gray,  crys- 
tals. 

3 

Emery 
Wheel 
Test. 

Few  steel  sparks  and 
then  iron  sparks 
from  interior. 

Bright,,  luminous 
sparks  that 
break  in  falling. 

Dull  red  sparks 
that  do  not 
break. 

4 

Chisel  Test 

Surface  will  curl  and 
interior  break  off. 

Will  curl  before 
breaking. 

Will  chip  off. 

5 

Torch  Test 

Gives  way  before 
flame  and  delivers 
few  sparks.  Metal 
becomes  porous. 

Gives  forth  bright 
sparks      that 
break  in  falling. 

Gives  no  sparks 
except  where 
there  are  im- 
purities. 

FIG.  43. 

grain.  When  the  torch  is  applied  a  distinctively  steel  spark 
which  is  luminous  and  breaks  in  falling  is  thrown  off.  When 
applied  to  the  emery  wheel  steel  sparks  are  thrown  off;  when 
the  edge  is  chipped  by  a  chisel  it  will  curl  up. 


WELDING  OF  CAST  IRON  61 

(68)  The  metal  in  the  filler-rod  should  be    the  same  in 
practically  all  cases  as  the  metal  to  be  welded.     There  are 
few  exceptions  to  this  rule,  but  the  principal  one  is  that  of 
malleable  iron.     The  cast  iron  in  the  rods  is  of  a  very  good 
grade  and  generally  much  better  than  the  piece  to  be  worked 
upon.     To  permit  the  ready  flow  of  the  rod  and  eliminate 
oxidation,  as  much  as  possible,  three  per  cent  of  silica  is  gen- 
erally used  in  the  casting  of  filler-rods  for  cast  iron  welding. 
Piston  rings  and  other  scrap  iron  should  not  be  used  for  filler- 
rods,   as  they  contain  many  impurities  s'uch  as  core-sand, 
dirt,  grease,  etc.,  which  will  ruin  the  weld.     It  is  dishearten- 
ing to  see  some  operators  attempt  to  economize  on  the  filler- 
rod.    It  is  not  an  uncommon  sight  to  see  several  dollars'  worth 
of  gas  and  the  same  amount  of  the  welder's  time,  together 
with  a  few  cents'  worth  of  filler  rods  all  lost,  and  the  opera- 
tor's    reputation    ruined.      This,    because     an    attempt    is 
made  to  save  the  few  cents  involved  in  the  filler-rods  by 
substituting  a  rod  of  a  very  poor  grade. 

(69)  A  flux  is  not  used,  as  many  suppose,  to  cement  the 
filler-rod  to  the  metal.     It  is  used  purely  as  a  cleansing 
agent  and  may  be  likened  to  the  acid  used  in  soldering. 
It  does  not  act  on  the  metal  until  the  latter  has  reached  the 
melting-point,  but  then  it  starts  to  break  up  the  oxides  and 
clean  the  surface.     This  action  permits  the  metal  to  flow 
together  more  readily.     A  cast-iron  flux  is  always  used  in 
welding   cast  iron,  to  break  up  the  oxide,  because  the  cast 
iron  itself  will  melt  before  the  oxide  and  no  matter  how  hot 
the  metal  is  it  will  not  flow  together  as  long  as  this  oxide  is 
present. 

(70)  To  obtain   the  best  results,  reliable  fluxes   should 
always  be  used.     Occasionally  an  accident  will  happen  to 
the  flux  can,  when  the  operator  is  on  some  isolated  job  and  a 
substitute  flux  must  be  obtained  at  once.     Equal  parts  of 
bicarbonate  of  soda  (cooking  soda),  and  carbonate  of  soda 


62 


OXY-ACETYLENE  WELDING  MANUAL 


(ordinary  washing  soda),  may  be  purchased  from  any  grocery 
in  the  powdered  form  and  mixed  together  thoroughly.  This 
will  tide  the  welder  over  until  he  can  return  to  the  shop  and 
replenish  his  supply. 

(71)  The  flux  is  generally  applied  by  means  of  the  filler- 
rod.  One  end  is  heated  and  dipped  in  the  flux;  enough  will 
adhere  to  break  up  part  of  the  oxides,  on  the  ordinary-sized 
job.  The  flux  is  carried  to  the  work,  which  should  be  at  the 
melting-point  and  introduced  between  the  flame  and  the  metal. 
Oxides  will  break  up  immediately  and  the  metal  will  flow 
together,  but  it  must  be  remembered  that  the  flux  has  no 


FIG.  44.— Whenever  Possible,  the  Beginner  should  "V"  His  Work,  and  Com- 
plete His  Weld  from  One  Side  only.  On  heavy  work,  however,  it  will 
be  necessary  to  "  V"  out  from  both  sides,  as  is  here  shown. 

action  on  cold  or  moderately  heated  metals.  The  flux  as 
has  been  explained  is  used  to  clean  the  metal  and  break  up 
the  oxides.  To  the  oft-repeated  question,  how  often  should 
the  flux  be  applied,  answer  is  made  as  follows:  As  often  as 
it  is  necessary  to  clean  up  the  metal  and  break  up  the  oxides. 
All  fluxes  should  be  kept  in  airtight  containers  when  not  in 
use,  to  keep  their  chemical  contents  in  the  very  best  condi- 
tion and  it  is  best  to  use  only  a  small  quantity  of  flux  on  the 
welding  table  at  one  time. 

(72)  Oxy-acetylene  welding  is  purely  a  fusing  process 
and  the  most  important  points  to  remember  in  executing 
a  weld  are,  to  eliminate  the  entire  crack  in  the  fracture  and 


WELDING  OF  CAST  IRON  63 

to  add  the  filler-rod  without  changing  the  character  of  the 
metal.  On  thin  pieces  of  metal  it  is  possible  to  depend  upon 
the  force  of  the  flame  to  entirely  penetrate  to  the  depth  of  the 
crack  but  on  work  three-eighths  of  an  inch  thick  or  over,  it 
is  well  to  "  V  "  out  or  remove  some  of  the  surface  metal  around 
the  crack  in  order  to  get  down  to  the  bottom.  By  "  V-ing  " 
we  mean  to  chip  or  grind  off  each  edge  at  an  angle  of 
approximately  45  degrees,  so  that  the  opening  will  form  an 
angle  of  90  degrees  where  the  two  pieces  come  together, 
with  the  crack  at  the  bottom  portion  of  the  "  V."  This  should 
NOT  be  ground  down  to  a  knife  edge,  for  it  will  readily  burn 
up.  It  is  preferable  to  leave  about  one-eighth  inch  along  the 
line  in  order  that  the  pieces  will  fit  together  and  the  proper 


FIG.  45. — Starting  a  Cast-iron  Weld. 

alignment  may  be  obtained.  If  two  pieces  of  cast  iron  have 
been  prepared  in  this  manner  the  neutral  flame  of  the  welding 
torch  is  brought  down  in  such  a  manner  that  the  tip  of  the 
cone  just  licks  the  metal.  The  heat  is  not  applied  directly  to 
the  line  of  weld  to  start  with,  but  rather  to  the  surrounding 
part.  This  is  done  in  order  to  get  the  entire  locality  in  a  con- 
dition which  will  not  withdraw  too  much  of  the  heat  from  the 
line  of  the  weld,  once  the  fusing  is  begun.  If  it  is  found  that 
the  tip  will  not  produce  enough  heat  to  bring  the  metal  to  a 
red  heat  in  a  fairly  short  time,  a  larger  tip  should  be  used. 

(73)  No  set  rule  can  be  given  as  to  the  sized  tip  to  be  used 
on  various  kinds  of  metal.  It  will  largely  depend  upon  the 
welder's  ability  and  judgment.  When  the  metal  is  brought 


64  OXY-ACETYLENE  WELDING  MANUAL 

to  red-heat,  the  neutral  flame  or  cone  is  brought  into  contact 
with  the  lowest  portion  of  the  "V"  and  held  there  until 
it  is  seen  that  the  metal  is,  melted  on  both  sides.  The  filler- 
rod,  which  has  previously  been  heated  at  one  end  and  dipped 
into  the  flux  so  that  an  amount  adheres  to  the  end  of  the  rod, 
then  carries  this  flux  to  that  portion  of  the  weld  which  is 
under  way.  Enough  flux  is  blown  off  the  rod  into  the  weld 
to  clean  up  the  surface  and  permit  the  metal  flowing  together. 
The  crack  should  be  melted  together  all  along  before  any 
additional  metal  is  added,  for  the  elimination  of  the  crack  is 
extremely  important.  It  might  be  noted  that  as  soon  as  the 
metal  begins  to  flow  freely  the  neutral  flame  should  be  raised 
a  short  distance  from  the  work  in  order  to  better  control  the 


FIG.  46. — Reinforcing  a  Cast-iron  Weld. 

molten  metal.  In  order  to  build  up  the  metal  to  the  original 
state  along  the  line  of  weld  or  perhaps  'reinforce  it,  the  sides 
and  bottom  of  this  "  V-ed  "  out  part  are  then  brought  to  a 
molten  state  arid  held  there  while  the  filler-rod  which  brings 
up  more  flux  is  stirred  into  this  metal  and  the  end  melted  off. 
In  this  way  the  flame  does  not  come  in  direct  contact  with 
the  filler-rod  and  is  used  only  to  keep  the  metal  in  a  molten 
condition.  As  much  of  the  filler-rod  can  be  melted  off  as  is 
thought  necessary  to  bring  the  weld  to  the  normal  condition 
of  the  metal  or  an  additional  reinforcement  can  be  built  up, 
if  it  is  thought  advisable.  If  care  is  taken  in  the  above  pro- 
cedure, many  of  the  blow  holes  and  hard  spots  in  the  weld  will 
be  eliminated,  for  any  impurities  that  might  gather  will  be 


WELDING  OF  CAST  IRON  65 

displaced  by  the  melted  metal  and  will  float  to  the  top. 
In  cooling  a  weld  of  this  kind,  care  should  be  taken  not  to 
permit  any  sudden  chilling  for  this  will  tend  to  harden  the 
weld.  It  is  best  to  cool  it  slowly  by  burying  it  in  slack  lime, 
ashes,  or  wrap  it  with  asbestos  paper  to  keep  the  air  from  it 
as  much  as  possible. 

(74)  There  may  be  a  great  many  causes  for  blow  holes  and 
hard  spots  in  the  weld,  but  probably  they  can  all  be  traced 
directly  to  the  lack  of  heat.  It  must  be  remembered  that 
welding  is  a  fusing  process  and  heat  is  absolutely  essential. 
Therefore  it  should  not  be  used  sparingly.  The  application 
of  heat  always  causes  expansion.  There  are  no  exceptions 


FIG.  47. — This  Problem  does  not  Require  Preheating  to  Care  for  Contraction, 
as  the  Ends  of  A  and  B.  are  not  Confined. 

to  this  rule,  likewise  upon  cooling  the  metal  there  will  be  a 
contraction.  Outside  of  the  actual  welding,  that  is,  the 
fusing  of  the  metal  into  a  homogeneous  mass,  perhaps  the 
greatest  problem  that  the  welder  has  to  confront  is  the  expan- 
sion and  contraction  of  his  metals.  Whenever  the  ends  of 
two  pieces  of  metal  which  are  to  be  welded  are  free  to  move, 
or  even  one  end,  there  will  be  no  difficulty  encountered  with 
contraction  and  expansion,  but  if  these  ends  are  confined,  it 
is  an  entirely  different  problem. 

(75)  To  illustrate  this  point  more  clearly,  the  following 
very  simple  example  will  be  given.  In  Fig.  47  we  have  two 
bars  of  metal  A  and  B  which  have  been  beveled  off  or  "  V-ed  " 


66 


OXY-ACETYLENE  WELDING  MANUAL 


out  as  shown  at  the  point  C.  Now  as  soon  as  the  heat  is 
introduced  at  C  there  is  bound  to  be  an  expansion  of  the  metal 
at  that  point.  Naturally  if  the  pieces  were  heated  slowly 
and  for  a  considerable  distance,  the  cool  ends  of  these  bars 
would  be  forced  outward.  We  will  assume  that  the  heat  is 
introduced  very  rapidly  and  the  metal  is  brought  to  a  molten 
state;  that  instead  of  the  contraction  forcing  the  cool  ends 
outward,  whatever  expansion  there  is,  is  taken  care  of, 
at  the  weld,  for  the  metal  when  melted  will  readily  push  to- 


FIG.  48. — Preheating  Problem.     Ends  ofvBars  A'  and  B'  are  Confined. 


gether.  It  is  also  assumed  that  the  bars  are  heavy  enough  to 
overcome  what  slight  force  might  be  in  evidence  from  the 
expansion.  A  weld  is  then  made  and  allowed  to  cool.  As 
it  cools,  there  is  bound  to  be  a  contraction  along  the  line  of 
the  weld  and  the  welded  piece  will  be  slightly  shorter  than  the 
work  before  the  weld,  for  it  will  draw  in  the  pieces  A  and  B. 
As  can  be  seen,  there  is  no  particular  force  preventing  the 
contraction  of  such  a  weld  for  the  ends  are  free  to  move. 
However,  let  us  turn  to  Fig.  48,  which  constitutes  an  entirely 
different  problem.  It  might  seem  that  the  ends  A'  and  Br 


WELDING  OF  CAST  IRON  67 

appear  the  same  as  A  and  B  in  Fig.  47,  but  such  is  not  the 
case.  The  ends  farthest  from  the  weld  are  confined,  held  in 
place  by  a  heavy  frame  which  does  not  permit  their  free 
movement.  When  heat  is  introduced  at  the  point  of  welding 
C",  about  the  same  action  takes  place  as  in  the  previous 
problem,  but  as  soon  as  the  weld  commences  to  cool  let  us 
see  what  happens.  The  bar  A'B'  must  be  shortened  so  there 
is  an  inward  pull  on  the  bars  D'  and  E' '.  If  this  work  were 
cast  iron  or  aluminum  it  would  certainly  be  broken  by  the 
strains  set  to  working  and  would  naturally  break  at  C',  where 
the  metal  is  still  hot.  If  it  were  steel  or  one  of  the  ductile 
metals,  it  might  twist  and  warp  in  its  endeavor  to  overcome 
these  internal  strains.  This  illustrates  in  a  very  simple 
manner  the  difference  between  what  is  known  as  a  "  cold  " 
and  a  "  preheating  "  job.  In  the  first  no  provision  is  made 
for  expansion  and  contraction.  In  the  second  means  are  taken 
to  overcome  these  important  factors.  In  order  to  provide 
for  the  successful  welding  of  the  second  problem,  it  is  only 
necessary  to  heat  up  the  bars  X  and  Y  about  the  same  distance 
as  the  center  will  be  heated,  and  keep  them  in  that  condition 
while  executing  the  weld  atC',  then  allowing  the  whole  to  cool 
gradually. 

PART  Two.— WELDING  OF  CAST  IRON 

(76)  BEFORE  commencing  to  weld,  or  even  turning  on  the 
gas,  it  is  well  to  see  that  all  preparations  have  been  made  and 
all  materials  on  hand  to  bring  the  weld  or  whatever  job  it 
may  be,  to  a  finished  state. 

(77)  As  a  specific  example  of  a  simple  welding  operation 
let  us  consider  that  two  cast-iron  bars,  measuring  one  by  six 
inches  and  twenty-four  inches  long  are  to  be  welded  end 
to  end.     To  start  with  it  would  be  necessary  to  "  V  "  off  the 
?nds  that  were  to  be  joined  at  an  angle  of  about  45  degrees, 


68  OXY-ACETYLENE  WELDING  MANUAL 

leaving  about  one-eighth  inch  along  the  bottom  edge  to  line 
the  metals  up  with  and  to  see  whether  they  are  in  proper 
position.  If  the  bar  were  to  measure  exactly  forty-eight 
inches  when  finished  it  would  be  necessary  to  move  these 


(Courtesy  of  Ben  K.  Smith,  U.  S.  Welding  Co.) 

FIG.  49. — This  Locomotive  Cylinder  was  Welded  at  the  Saddle,  near  the 

Frame. 


bars  apart  about  one-sixteenth  of  an  inch  in  order  to  provide 
for  their  contraction.  It  is  assumed  that  the  weight  of 
the  bars  would  be  sufficient  to  prevent  their  pushing  apart 
when  the  line  of  the  weld  is  brought  to  a  molten  state  and  that 


WELDING  OF  CAST  IRON  69 

the  expansion  will  be  taken  care  of  within  the  weld.  The 
bars  after  being  lined  up  are  ready  for  welding,  but  there 
are  such  things  as  filler-rods,  flux  and  goggles  that  are  neces- 
sary to  have  on  hand  before  starting  to  work.  It  is  well 
to  have  a  few  fire  bricks,  a  little  asbestos  paper  and  a  bucket 
of  water  convenient,  in  case  these  things  are  needed.  The 
acetylene  gas  should  then  be  turned  on  and  ignited.  A  suf- 
ficient pressure  should  be  passing  through  the  regulator,  when 
using  a  medium,  or  high-pressure  apparatus,  to  cause  the 
flame  to  leave  the  torch  tip  about  twice  the  distance  of  the 
diameter  of  the  orifice  of  that  particular  tip.  Then  turn  on 
the  oxygen  until  a  neutral  flame  is  obtained.  On  some 
torches  it  is  necessary  to  make  a  second  adjustment  by 
turning  on  a  little  more  acetylene  gas  and  still  more  oxygen, 
until  a  goodly  sized  neutral  flame  results.  Apply  the  flame 
to  the  pieces,  so  that  the  neutral  flame  will  just  lick  the  sur- 
face of  the  metal.  Move  the  torch  slowly  forward  and  back- 
ward on  each  side  of  the  "  V  "  until  the  two  edges  are  a  dull 
red  color,  or  better  still  a  bright  cherry  red,  then  hold  the  torch 
stationary  until  the  metal  in  the  "  V  "  nearest  to  the  operator 
commences  to  melt.  Then  bring  the  filler-rod  end  in  contact 
with  the  flame  to  get  it  heated  and  plunge  it  into  the  flux 
which  should  be  near  at  hand.  Enough  flux  will  adhere 
to  break  up  the  oxides  and  by  placing  the  rod  between  the 
flame  and  the  metal,  enough  flux  will  be  introduced  to  allow 
fusing  of  the  metal.  Proceed  in  this  manner  until  the  metal 
in  the  bottom  of  the  "  V  "  is  properly  fused  throughout 
its  length.  Do  not  add  the  filler-rod,  up  to  this  point  unless 
necessary.  In  holding  the  flame,  see  that  the  preheating 
flame  will  heat  the  parts  yet  to  be  welded.  The  weld  should 
be  made  away  from  the  operator.  After  the  metals  along 
the  bottom  have  united  and  a  good  foundation  has  been 
obtained,  then  start  the  weld  at  the  beginning  once  more, 
working  the  flame  across  the  piece,  in  the  same  manner  as 


70  OXY-ACETYLENE  WELDING  MANUAL 

before;  bringing  the  metal  to  the  molten  state  and  stirring 
the  filler-rod  in  it.  As  the  filler-rod  melts,  the  amount  of 
molten  metal  naturally  increases  and  the  flame  is  moved 
along  the  weld  as  fast  as  the  metal  is  added.  It  is  important 
that  the  metal  is  in  a  molten  condition.  It  is  almost  im- 
possible to  get  too  much  heat  on  this  type  of  work.  Build 
up  the  weld  slightly  higher  than  the  original  piece.  It  may  be 
found  in  finishing  up  the  corners  that  the  velocity  of  the  gases 
or  the  force  of  the  flame  will  be  sufficient  to  blow  the  melted 
metal  away.  This  may  be  overcome  by  directing  the  flame 
at  a  different  angle,  and  will  cause  no  difficulty  after  a  little 
practice.  Trouble,  too,  may  be  experienced  on  thin  cast- 
iron  sections  by  having  the  metal  collapse  through  the  force 
of  the  flame,  but  this  can  be  remedied  in  the  same  manner. 
While  the  weld  is  still  in  a  heated  condition,  it  is  possible  to 
finish  it  by  scraping  the  surplus  metal  off  with  the  side  of  the 
filler-rod,  the  chill  of  which  has  been  taken  off  before  it  is 
allowed  to  come  in  contact  with  the  molten  metal.  Another 
popular  method  that  will  produce  even  better  results  is  to 
use  a  very  heavy  rasp  file  to  bring  the  weld  down  to  the  meas- 
urements desired.  During  all  of  the  previous  operations  the 
flame  never  leaves  the  line  of  weld.  When  the  weld  is  com- 
pleted, the  torch  is  shut  down  by  turning  off  the  oxygen 
first,  and  then  the  acetylene,  and  the  welded  bar  is  covered 
up  to  prevent  its  cooling  too  rapidly. 

PART  THREE.— WELDING  OF  CAST  IRON 

(78)  PROBLEMS  in  expansion  and  contraction  should  not 
be  difficult,  if  it  is  remembered  that  heat  causes  expansion 
and  the  withdrawal  of  heat,  or  cooling  causes  contraction. 
As  previously  stated,  when  the  ends  of  the  pieces  which  are 
being  welded  are  free  to  move,  there  is  not  much  danger  of 
having  contraction  strains  set  up.  Where  the  ends  are  con- 


WELDING  OF  CAST  IRON  71 

fined,  measures  must  be  taken  to  overcome  this.  In  welding 
large  pulley  wheels,  for  example,  it  may  be  advisable  to  do 
the  job  without  taking  time  to  preheat.  Breaks  may  be 
in  evidence  at  any  part  of  the  wheel  and  generally  the  ends 
are  confined,  such  as  in  the  case  of  a  spoke.  If  it  is  borne  in 
mind  that  the  expansion  will  take  care  of  itself,  the  contrac- 
tion is  the  only  consideration,  in  a  case  of  this  kind.  The 
welder  will  see  that  if  he  can  spring  the  edges  apart  a  sufficient 
amount  to  provide  for  the  spoke  coming  back  to  normal  when 
welded,  he  will  have  no  difficulty.  The  way  to  proceed  in  a 
case,  of  this  kind  would  be  to  open  the  rim  by  sawing  it  and 
then  introduce  a  jack  or  some  sort  of  a  wedge  between  the 
hub  and  the  rim.  This  will  open  the  crack  in  the  spoke  the 
amount  desired.  As  soon  as  the  weld  is  executed  and  while 
still  hot,  the  jack  is  removed  to  permit  the  rim  being  drawn 
in.  Later  the  rim  can  be  welded,  by  introducing  jacks  be- 
tween the  spokes  and  the  same  procedure  followed.  It 
always  must  be  remembered  that  provision  must  be  made 
for  the  contraction,  even  though  it  be  only  one  thirty-second 
or  one-sixteenth  of  an  inch.  The  distance  will  depend  en- 
tirely upon  the  welder,  as  some  operators  use  small  tips  and 
cover  a  small  area,  while  others  employ  larger  tips  and  cover 
twice  the  area.  It  is  therefore  impossible  to  set  any  specific 
distance  and  each  welder  should  try  to  figure  this  out  for 
himself. 

(79)  There  are  many  jobs  not  of  a  preheating  nature 
that  at  times  cause  perplexity  on  the  part  of  the  welder.  A 
good  example  of  this  is  a  cast-iron  gear  wheel.  A  number  of 
its  teeth  have  been  broken  out.  Now  there  are  three  very 
common  ways  of  building  up  or  repairing  such  castings. 
First  by  aid  of  carbon  blocks,  cut  to  form  and  the  teeth  cast 
in  by  the  use  of  the  torch;  second,  by  blanking  in  the  space 
between  the  teeth  and  then  sawing  out  the  individual  tooth 
or  cutting  it  out  with  a  milling  machine  or  shaper;  third,  by 


72 


OXY-ACETYLENE  WELDING  MANUAL 


building  up  each  tooth  with  the  welding  rod  and  torch, 
and  later  dressing  it  down  with  a  file.  One  very  important 
point  must  be  uppermost,  when  dental  work  on  gears  is  being 
done,  a  good  foundation  is  necessary,  for  regardless  of  how 
well  the  tooth  may  be  shaped,  if  it  is  not  firmly  secured  to  the 
wheel  itself,  it  will  be  of  very  little  value.  Another  very 


eld  Eqttipment  Co.) 

FIG.  50.— Large  Cast-iron  Gear  Wheels.  Although  the  Face  on  These  Gears 
Measured  10  Inches,  New  Teeth  were  Added  by  Blanking  In,  as  Shown 
in  the  Right-hand  View,  and  Later  Machined. 

important  point  is  in  the  finishing  of  such  gears,  to  see  that 
the  teeth  which  have  been  added  correspond  in  the  pitch 
and  mesh  exactly  as  the  others  do.  The  importance  of  seeing 
that  things  of  this  nature  are  machined  correctly  should  not 
require  mention,  but  it  has  often  been  found  that  machinists 
are  very  careless  about  finishing  this  kind  of  work  and  if 


WELDING  OF  CAST  IRON  73 

anything  goes  wrong,  the  welder  is  naturally  at  fault.  There- 
fore it  is  always  well  to  put  the  gears  which  have  been  welded 
back  into  place  and  turn  them  over  slowly  by  hand  to  see  that 
they  are  in  good  condition  before  the  power  is  turned  on. 
In  allowing  this  kind  of  work  to  cool  after  it  has  been  welded, 


(Courtesy  of  the  Oxweld  Acetylene  Co.) 

FIG.  51.— This  View  Shows  new  Teeth  being  Welded  in  an  8^-ft.  Cast-iron 
Gear,  Weighing  over  5  Tons.    Note  the  Improvised  Preheating  Oven. 

some  operators  permit  it  to  be  hurried,  with  the  result  that 
there  may  be  hard  spots  to  confront  the  machinist  when 
finishing.  If  he  ruins  one  or  two  of  his  cutters  he  will  naturally 
frown  upon  all  welding  work.  It  is  therefore  desirable  for 
this  and  many  other  reasons  to  have  the  weld  come  out  as 


74  OXY-ACETYLENE  WELDING  MANUAL 

soft  as  possible,  and  great  care  should  be  exercised  in  cooling. 
Any  weld  that  is  subjected  to  machining,  allow  it  to  cool 
slowly  in  slack  lime,  in  ashes,  or  cover  it  securely  with  asbestos 
paper.  Occasionally  it  may  be  found  difficult  to  find  sections 
of  carbon  blocks  which  will  take  care  of  a  job  of  this  kind. 
Many  welders  who  have  had  to  run  around  the  country, 
and  do  jobs  in  isolated  places,  have  found  that  the  carbon 
centers,  from  the  ordinary  dry  cell  batteries,  which  may  be 
found  practically  everywhere  in  a  discarded  condition,  can 
be  shaped  on  an  emery  wheel  and  patched  together  in  a  manner 
that  will  permit  their  use.  However,  when  such  are  used, 
it  is  quite  necessary  that  they  be  heated  a  little  with  a  torch 
beforehand,  in  order  to  drive  out  any  chemicals  or  acids 
that  may  be  contained  in  them.  Unless  these  chemicals  are 
removed,  the  molten  metal  coming  in  direct  contact  with 
them  might  be  injured  to  a  considerable  extent. 

(80)  Ofttimes  there  are  castings  upon  which  parts  wear 
off  in  a  very  short  time.  There  may  be  very  little  strain 
upon  these  parts,  yet  the  constant  wear  will  weaken  them  in 
time.  It  is  well  to  remember  the  action  of  a  carbonizing 
flame  when  executing  work  of  this  kind.  Introduce  an 
excess  of  acetylene  when  finishing  up  the  work.  It  will  be 
found  that  with  a  strongly  carbonizing  flame,  carbon  will 
be  taken  up  by  the  molten  metal  and  the  finished  weld  will 
be  considerably  harder  and  will  wear  longer  than  if  it  were 
executed  by  a  neutral  flame.  An  abrupt  cooling  will  chill 
the  metal  on  the  surface  and  make  it  wear  longer  than  it 
would  otherwise. 


WELDING  OF  CAST  IRON 


75 


PART  FOUR.— WELDING  OF  CAST  IRON 

(81)  THE  true  index  as  to  the  success  of  a  weld  will  depend 
entirely  upon  the  finished  job.  If  it  is  usable,  i.e.,  if  it  can 
be  put  back  into  service  again  and  give  satisfaction,  it  may  be 
considered  a  successful  weld.  If  a  piece  were  to  be  warped, 
distorted,  contain  hard  spots  which  could  not  be  machined, 
or  have  internal  strains,  which  would  not  make  it  safe  for 


(Courtesy  of  Ben  K.  Smith,  V.  S.  Welding  Co.) 

FIG.  52. — View  of  Locomotive  Cylinder  with  Three  Jackets  3  Inches  Thick. 
This  job  weighed  over  16  Tons  and  Required  Fifty-six  Hours  of  Welding. 

use  (such  as  fly- wheels),  it  could  not  then  be  considered 
satisfactory  and  it  would  be  only  wasted  energy.  Perhaps 
one  of  the  most  common  jobs  in  the  ordinary  commercial 
shop,  and  one  which  is  the  most  abused,  is  the  common  cast- 
iron  cylinder  block  found  on  the  gasoline  engine.  This  is 
so  constructed  that  there  are  two  walls  of  metal,  very  thinly 
cast;  the  innermost  being  the  cylinder  wall,  and  the  outer- 


76  OXY-ACETYLENE  WELDING  MANUAL 

most  a  water-jacket.  The  cylinder  wall  is  machined  very 
accurately  to  accommodate  pistons  moving  at  a  very  rapid 
rate,  up  and  down  and  yet  holding  compression.  The 
upper  part  of  the  cylinder  is  called  the  head,  and  generally 
has  two  or  more  valve  seats  which  must  be  in  alignment 
with  the  valve  guides  to  make  an  airtight  seat  for  the  valves. 
Now  this  water-jacket  is  usually  very  thin,  perhaps  three- 
sixteenths  to  one-quarter  inch  in  thickness,  and  when  there  are 
two,  three,  four,  or  more  cylinders  cast  in  one  block,  there  are 
bound  to  be  internal  strains  set  up  in  casting  within  the 
piece  itself.  These  strains  are  removed  to  a  large  extent 
by  baking  the  rough  casting  before  machining.  Generally 
there  are  some  strains  left  in  every  cylinder  block  of  this 
nature.  If  the  water  in  the  water-jacket  freezes  or  some 
other  force  comes  in  contact  with  the  thin  castings  which  con- 
stitute a  block,  the  metal  will  give  way  at  its  weakest  point, 
and  the  welder  is  usually  called  upon  to  repair  it.  At  times 
these  cracks  are  exceedingly  small  and  the  temptation  is  to 
braze  or  attempt  to  weld  the  small  portions.  However, 
as  soon  as  there  is  heat  introduced  into  the  water-jacket  and 
not  into  the  cylinder  wall,  there  are  certain  to  be  strains  set 
up  which,  if  sufficient,  will  distort  the  cylinder  and  make  it 
useless  unless  it  is  rebored.  The  sooner  welders  realize  that 
work  of  this  nature  must  be  preheated  throughout,  to  a 
point  as  near  melting  as  they  can  approach  without  causing 
the  metal  to  scale,  before  any  welding  is  attempted,  the 
better  success  will  be  obtained  in  these  lines.  It  is  quite 
necessary  to  line  up  the  work  well,  so  that  it  will  not  sag 
when  heated.  It  is  best  to  heat  very  slowly  and  cool  in  the 
same  manner  to  insure  the  best  results.  There  are  many 
preheating  agencies,  such  as  oil-ovens,  preheating  torches 
and  the  like,  but  about  the  best  and  most  reliable  agent 
known  is  charcoal,  which  heats  up  very  gradually,  makes 
a  good  even  fire  and  dies  down  slowly  which  is  the  manner 


WELDING  OF  CAST  IRON 


77 


"'-•  -U-- 

• 


8  OXY-ACETYLENE  WELDING  MANUAL 

desired.  Occasionally  cracks  will  be  found  in  the  combus- 
tion head  of  the  cylinder.  It  is  very  difficult  to  get  the 
torch  down  inside  the  cylinder  to  execute  this  weld  unless 
the  operator  has  a  special  torch  for  this  purpose.  Even  then 
it  is  difficult  to  keep  the  torch  lighted  when  working  over  a 
newly  made  charcoal  fire.  For  this  reason,  other  means 
must  be  used  when  working  on  a  job  of  this  kind.  First 
the  crack  is  accurately  located,  then  a  piece  is  cut  out  of  the 
water-jacket  just  over  the  crack  by  means  of  a  chisel,  hack- 
saw or  drill  press.  Never  attempt  to  remove  a  piece  of  this 
nature  with  the  flame,  for  the  introduction  of  heat  may  dis- 
tort the  piece  at  this  time.  "  V  "  out  the  crack  in  the  com- 
bustion head  and  scrape  off  as  much  of  the  brown  oxide  and 
dirt  formation  as  possible.  It  is  well  to  clean  off  more  than 
needed  and  to  even  "  V  "  out  the  crack  a  greater  distance  than 
is  thought  necessary.  This  will  insure  a  good  weld  being 
made  in  one  operation.  The  cylinder  is  then  preheated  with 
the  crack  uppermost  so  that  welding  can  be  executed  with  the 
least  possible  difficulty.  While  preheating  is  taking  place 
it  is  well  to  tack  the  small  section  of  the  water-jacket  which 
has  been  removed,  to  the  end  of  the  filler-rod,  and  place  it 
too,  in  the  preheating  oven,  with  the  end  of  the  filler-rod 
projecting  so  that  it  will  be  available  whenever  needed. 
When  the  cylinder  is  red  hot  the  weld  should  be  executed; 
particular  attention  being  given  to  see  that  each  part  of  the 
metal  is  actually  fused  to  prevent  any  leaks  occurring  later. 
As  a  rule  the  welder  can  tell  when  he  has  made  a  successful 
weld  by  observing  the  flow  of  his  metal,  and  it  will  not  be 
necessary  for  him  to  test  out  this  cylinder  weld  before  adding 
the  water-jacket.  The  piece  of  the  water-jacket  is  then 
replaced;  it  can  be  very  easily  handled  by  means  of  the 
filler-rod  which  has  been  tacked  on.  Weld  this  section  securely 
in  place  and  cover  the  piece  of  work  with  asbestos  paper  and 
permit  it  to  cool  with  the  dying  fire.  When  cold,  all  port 


WELDING  OF  CAST  IRON 


79 


holes  in  the  water-jacket  should  be  closed  and  the  cylinder 
tested  for  leaks.  This  can  be  done  by  introducing  water 
into  the  water-jacket  and  applying 
about  fifteen  pounds  of  air  pressure. 
Wet  spots  will  appear  if  there  are 
any  leaks.  If  the  cylinder  is  found 
tight  it  should  be  polished,  then 
oiled,  and  the  outside  given  a  coat 
of  filler  or  painted  to  make  it  pre- 
sentable. Work  is  generally  very 
much  discolored  when  coming  out 
of  the  fire.  A  simple  device  for 
polishing  the  cylinder  bore  may  be 
made  by  turning  out  a  hardwood 
block  about  three  inches  long  and  FIG.  ^.-Suggested  Method  of 
a  little  less  in  diameter  than  the  Polishing  Cylinder  Walls  of 
size  of  the  piston.  This  should  be  Cast-iron  Cylinder  Block 

,.  .  •        -r^.  after  it  has  been  Preheated. 

split   as    shown    in    Fig.    54,    and 


FIG.  55. — Cast-iron  Cylinder 
Block  with  Part  Broken 
Off. 


FIG.  56. — Showing  how  Broken  Part 
on  Cast-iron  Block  should  be  Lined 
up  before  Welding.  Position  Great- 
ly Exaggerated. 


80  OXY-ACETYLENE  WELDING  MANUAL 

wrapped  with  very  fine  emery  cloth,  then  put  into  the  cyl- 
inder and  a  wedge  placed  between  the  two  halves.  Spread 
them  apart  so  they  will  come  in  contact  with  the  cylinder 
wall  on  all  sides.  A  screwdriver  may  be  used  for  this  purpose 
if  necessary.  By  screwing  this  into  the  cylinder  its  full 
depth,  with  the  aid  of  a  little  oil,  a  very  highly  polished 
surface  may  be  obtained. 

(82)  Another  cylinder  block  job  that  generally  causes 
more  confusion  than  is  necessary  is  brought  about  when 
welding  on  small  lugs,  such  as  shown  in  Fig.  55.  When 
welding  these  lugs  on  from  the  outside  only,  they  generally 
warp  upwards  in  cooling  and  it  is  either  necessary  to  build 
up  the  bottom  side  of  this  lug  or  to  machine  off  the  entire 
face  in  order  to  have  the  end  square.  This  can  easily  be 
overcome  by  permitting  the  lug  to  sag  before  welding  and 
then  dress  off  the  small  portion  that  continues  to  sag,  after  it 
is  welded,  rather  than  face  off  the  whole  surface,  See  Fig.  56. 


CHAPTER  VII 
PART  ONE.— STEEL  WELDING 

(83)  THE  term  "  steel,"  as  used  in  the  following  pages, 
unless  otherwise  specified,  will  be  the  term  applied  to  wrought- 
iron  and  low-carbon  steels.     High-carbon  and  alloyed  steels 
are  to  be  considered  only  in  advanced  work  and  will  therefore 
not  be  deemed  a  topic  of  interest  to  the  beginner  in  laying 
his  foundation. 

(84)  The  welding  of  steel  is  much  more  difficult  than  cast 
iron  on  account  of  the  many  points  which  must  be  observed. 
In  cast  iron  the  metal  is  brought  to  a  molten  state  and  may  be 
worked  in  that  condition  for  some  time  without  any  apparent 
change  in  the  characteristics  of  the  metal.     A  flux  is   used 
to  break  up  the  oxide  or  scale  and  the  metal  will  flow  very 
easily.     The  flux  is  necessary  because  the  oxide  has  a  higher 
melting-point  than  the  iron  itself.     When  working  on  steel, 
it  will  be  observed  that  just  the  reverse  is  true,  that  its  oxide 
has  a  lower  melting-point  than  the  steel  and    consequently 
no  flux  or  cleaning  powder  is  necessary  when  working  upon  it. 

(85)  A  large  quantity  of  steel  kept  in  a  molten  condition 
by  the  flame  acting  upon  it  is  very  easily  influenced.     The 
same  area  is  not  kept  in  a  molten  condition  as  with  cast  iron. 
The  heat  does  not  hold  to  the  vicinity  of  the  weld  nearly 
so  much  as  in  cast  iron  because  of  the  greater  conductivity 
of  the  metal.     If  the  flame  is  removed,  the  molten  metal  will 
set  almost  immediately.     This  means  that  the  flame  must 
be  in  contact  with  the   metal  at  all    times.     It   must  be  a 
strictly  neutral  flame  or  else  one  of  the  two  gases  will  be  intro- 

81 


82  OXY-ACETYLENE^WELDING  MANUAL 

duced  into  the  weld  and  its  strength  will  be  materially  affected. 
The  size  of  this  flame  must  be  such  that  too  great,  an  area 
will  not  be  covered,  yet  enough  must  be  covered  to  keep  the 
metal  along  the  line  of  the  weld  in  a  molten  condition.  If 
a  carbonizing  flame  is  used,  one  which  has  an  excess  of  acety- 
lene, such  as  was  shown  in  Fig.  23,  much  carbon  will  be  taken 
up  by  the  metal,  producing  a  brittle  weld.  If  the  flame  is 
oxidizing,  that  is,  contains  an  excess  of  oxygen  which  is  noticed 
by  the  shortening  of  the  flame  and  an  accompanying  hissing 
sound,  Fig.  25,  the  metal  will  burn  and  a  white  foam  will 
appear  on  the  weld  like  a  milky  white  glue.  This  tends  to 
weaken  the  weld.  This  same  effect  will  be  in  evidence  if 
too  large  a  tip  is  used.  On  the  other  hand  if  the  tip  is  too 
small  not  enough  heat  is  obtained  and  the  oxides  and  other 
impurities  which  may  be  present  will  not  be  allowed  to  float 
to  the  surface  but  will  be  trapped  in  the  weld. 

(86)  The  filler-rod  used  on  steel  should  be  as  near  the 
same  grade,  if  not  better  than  the  metal  to  be  welded  and 
should  be  very  low  in  its  carbon  content.     A  pure  grade  of 
soft  iron  wire  or  mild  steel  will  make  a  very  good  filler-rod 
for  ordinary  purposes.     The  size  of    this  filler-rod  is  very 
important,  for  it  should  fuse  at  the  same  time  as  the  metal 
being  worked  upon,  and  unless  it  does  this  the  weld  will  not 
be  satisfactory.     If  the  fillerTrod  is  too  large  it  will  not  be 
at  the  fusion  point  when  the  work  is,  and  will  not  fuse  with 
it.     If  the  rod  is  brought  to  a  melting-point  the  work  will 
have  too  much  heat  and  will  burn.     On  the  other  hand, 
if  the  filler-rod  is  too  small,  it  will  burn  up  before  the  work 
is  at  the  fusion  point,  or  in  other  words,  the  work  will  still 
be  too  cold  when  the  rod  is  melted. 

(87)  There  are  many  different  methods  of  executing  a 
steel  weld,  and  it  has  been  noted  that  very  few  experienced 
welders  handle  their  steel  in  the  same  manner.     Most  of  these 
methods  are  very  difficult  to  learn  and  can  be  perfected  only 


STEEL  WELDING  83 

after  years  of  practice.  However,  a  simple  method  which  will 
produce  results  is  thought  the  most  advisable  for  the  beginner. 
A  careful  examination  and  study  of  this  point  has  brought 
out  the  following  method,  which  is  very  easily  picked  up  and 
which  dispenses  with  most  of  the  torch  movements  that  are 
generally  advocated  by  the  old  time  welders. 

(88)  When  welding  two  pieces  of  steel  bars,  the  cross- 
section  of  which  will  measure  one-half  inch  by  three  inches, 
they  are  beveled  off  and  prepared  in  the  manner  illustrated 
in  Fig.  57,  either  by  means  of  a  chisel,  file,  or  by  the  use  of  a 
grinding  wheel.  About  an  eighth  of  an  inch  of  the  original 


FIG.  57. — Preparing  and  Heating  Steel  before  Welding. 

stock  is  left  on  the  bottom  side  and  the  angle  formed  from 
these  two  places  when  brought  together,  should  be  90  degrees. 
When  the  pieces  have  been  prepared  and  placed  in  the  posi- 
tion shown  in  the  illustration,-  the  neutral  flame  is  then 
brought  down  at  right  angles  to  the  plane  of  the  metal,  so  that 
the  end  of  the  cone  will  just  lick  the  surface.  It  is  moved 
up  and  down  upon  each  side  of  the  part  to  be  welded  until 
each  piece  is  brought  to  a  red  heat,  for  a  distance  of  at  least 
one  inch  back.  The  position  of  the  torch  during  this  opera- 
tion can  be  seen  in  Fig.  57.  From  this  time  on,  the  operator 
should  work  as  rapidly  as  possible,  for  the  quicker  the  fusion 


84  OXY-ACETYLENE  WELDING  MANUAL 

of  the  metal  is  brought  about,  the  less  oxide  or  scale  will 
appear  and  a  better  weld  will  result.  The  description  of 
this  process  may  take  some  length  but  the  actual  fusion  not 
nearly  so  long. 

(89)  When  the  red-hot  stage  is  reached,  the  neutral  flame 
is  brought  down  to  the  very  lowest  part  of  the  "  V  "  at  the 
side  nearest  the  operator  and  held  there  until  the  metal  has 
melted  and  is  about  to  collapse.  The  flame  is  then  quickly 
twisted  away  for  just  a  second  to  let  the  metal  set.  Perhaps 


FIG.  58.— In  Welding  Steel,  the  Beginner  Should  Fuse  His  Pieces  together 
aldng  the  Bottom  with  the  Torch  Flame,  Adding  no  New  Metal.  The 
Metal  on  Both  Sides  of  the  Torch  Flame  is  Melted  together  until  a  Small 
Pool  of  Molten  Metal  Appears,  then  the  Torch  is  Twisted  Smartly  away, 
as  Shown  by  the  Arrow,  and  the  Metal  Allowed  to  "Set"  for  an  Instant 
before  Proceeding  along  the  Line  of  Weld. 

this  operation  will  fuse  about  one-half  inch  or  less  along  the 
bottom  of  the  "  V."  This  same  operation  is  repeated  along 
the  line  of  weld  until  the  whole  piece  is  fused  along  the  bot- 
tom. It  will  be  noted  that  no  filler-rod  has  as  yet  been  used. 
After  the  last  portion  has  been  fused,  the  flame  is  brought 
back  to  the  starting-point  and  played  not  only  on  the  bottom, 
which  has  already  been  fused,  but  on  the  sides  of  the  "  V  " 
as  well,  bringing  an  area  of  about  one  inch  in  diameter  to  a 
molten  condition.  The  tip  of  the  welding  torch  is  held  in  a 
vertical  position  all  this  time  to  Introduce  as  much  heat  into 


STEEL  WELDING  85 

the  weld  as  possible.  During  this  operation  the  filler-rod, 
which  should  measure  three-sixteenths  or  one-quarter  inch 
in  diameter,  is  picked  up  by  the  operator's  free  hand  and  its 
end  brought  near  the  heat  of  the  flame  so  that  it  may  be 
warmed  and  will  not  chill  the  metal  when  introduced  into  the 
weld.  When  the  melted  metal  is  running  freely,  the  tip  of 
the  welding  torch  is  slowly  inclined  in  the  direction  of  the  part 
to  be  welded  and  is  advanced  along  the  "  V-ed  "  out  portion 
at  this  angle  as  rapidly  as  the  metal  can  be  made  to  melt. 
This  position  is  shown  in  Fig.  59.  It  will  be  noted  that 


FIG.  59.— Method  of  Adding  "Filler-rod"  in  Welding  Steel.     Note  that  the 
Rod  is  Worked  behind  the  Flame. 

as  the  flame  advances  along  the  line  of  the  weld  the  molten 
metal  will  mount  up  behind  it  of  its  own  accord,  providing 
the  metal  is  in  a  molten  condition,  when  the  flame  passes  over 
it.  During  this  period  the  filler-rod  is  stirred  into  the  molten 
metal  in  a  circular  movement  which  should  be  in  back  of 
the  torch  as  much  as  possible.  This  means  that  the  torch 
comes  in  contact  with  the  filler-rod  but  very  little  and  the  rod 
is  melted,  not  by  the  flame,  but  by  the  molten  metal  of  the 
piece  being  welded.  It  will  be  noticed  at  times,  when  too 
much  metal  has  been  welded  and  the  torch  is  not  advancing 
rapidly  enough,  that  some  of  the  molten  metal  will  run  ahead 


86  OXY-ACETYLENE  WELDING  MANUAL 

of  the  flame,  into  that  part  of  the  "  V  "  yet  to  be  fused,  and 
to  the  unwary  student  this  will  be  looked  upon  as  a  safe  place 
to  add  his  filler-rod.  However,  when  the  piece  is  broken 
and  the  cross-section  of  the  weld  examined,  it  will  be  found 
that  in  this  part  of  the  weld,  the  metal  has  only  been  laid  on 
and  not  fused.  The  beginner  should  watch  this  operation 
and  see  to  it  that  this  molten  metal  is  not  permitted  to  run 
ahead  of  his  torch,  an  act  which  he  can  overcome  by  the  proper 
manipulation  of  his  filler-rod,  which  really  governs  all  the 
melted  metal  behind  the  flame.  If  not  enough  metal  has 
been  added  to  fill  in  the  "  V  "  to  the  proper  thickness,  this 


FIG.   60. — This  Method  of  Adding   the   "Filler-rod"   when  Welding  is  not 
Recommended  for  the  Beginner. 

operation  can  be  repeated  until  enough  metal  has  been  added. 
By  practicing  this  method  the  student  can  be  taught  to 
execute  a  very  successful  weld  and  reinforce  it  all  in  one 
operation  without  any  chance  of  burning  his  filler-rod  or 
lapping  his  metal.  More  practice  is  required  to  successfully 
weld  steel  than  most  other  metals  and  the  beginner  should 
not  be  discouraged  if  it  takes  him  some  time  to  conquer  this 
metal.  It  should  be  forcibly  impressed  on  the  student 
that  the  metal  must  be  in  a  molten  condition  before  the  filler- 
rod  is  added,  or  else  it  will  stick  and  prevent  his  working 
readily  and  in  addition  will  produce  a  very  faulty  weld. 


STEEL  WELDING  87 

Fusion  is  the  thing  to  bear  in  mind  for  without  it  success  can- 
not be  expected. 

(90)  While  outside  appearances  should  not  be  considered 
as  a  prime  requisite,  when  beginning  it  is  always  well  to  add 
more  metal  than  is  really  necessary  in  order  to  reinforce  the 
weld  as  much  as  possible.     It  cannot  be  expected,  however, 
that  a  steel  with  the  same  cross-section  as  the  original  will 
possess  the  same  properties  and  be  as  strong,  for  a  weld  is 
only  a  casting  unless  treated  otherwise  and  the  steel  or  wrought 
iron  used  in  the  specimens  is  of  rolled  stock.     If  too  much 
metal  has  been  added  and  dressing  down  is  necessary,  the 
student  will  find  that  by  using  a  slightly  oxidizing  flame  the 
surplus  metal  can  be  burnt  away  very  rapidly  and  a  very 
good-looking  job  can  be  executed  much  more  rapidly  than  if 
a  neutral  flame  were  used.     It  is  well  to  remember,  however, 
that  this  is  used  only  in  dressing  off  pieces  and  in  places 
where  the  strength  of  the  weld  is  not  to  be  jeopardized. 

(91)  When  advancing  in  steel  work,  it  will  be  noticed  that 
the  same  provision  for  contraction  and  expansion  is  not  con- 
sidered in  as  great  proportions  as  on  cast  iron,  and  the  reason 
is  quite  evident.     In   cast  iron  we  find   the  metal  is  very 
brittle  and  will  not  give  without  breaking,  whereas  on  steel 
it  is  more  ductile  and  will  twist  and  bend  before  breaking. 
This  does  not  mean,  however,  that  the  important  points  of 
expansion  and  contraction  are  to  be  neglected  in  steel  work, 
for  they  are  very  important;  as  we  shall  see  later  on. 

PART  Two.— STEEL  WELDING 

(92)  IT  is  still  supposed  that  the  beginner  knows  very  little 
about  the  various  kinds  of  metals,  or  methods  of  distinguish- 
ing between  them.     This  is  of  great  importance  and  should 
at  once  be  overcome,  as  he  will  not  at  all  times  have  someone 
over  him  to  diagnose  his  case  and  tell  him  the  proper  procedure. 


88  OXY-ACETYLENE  WELDING  MANUAL 

For  instance,  were  he  to  be  given  a  piece  of  cast  steel  to  weld, 
thinking  that  it  was  cast  iron,  he  would  use  a  cast-iron 
filler-rod  in  executing  his  weld.  The  results  of  such  a  weld 
would  not  be  very  favorable,  and  the  same  would  hold  true 
if  a  steel  filler-rod  were  used  on  cast  ifon.  An  occasional 
glance  at  the  table  in  paragraph  67  will  acquaint  him  with  the 
various  tests  to  make  when  deciding  upon  the  nature  of 
the  piece  to  be  worked  upon.  The  tests  should  be  applied 
in  every  doubtful  instance.  When  working  on  cast  steel, 
a  student  may  think  that  he  must  have  a  cast-steel  filler-rod, 
but  this  is  an  exception  to  the  general  rule  and  he  can  use 
the  same  style  filler-rod  as  he  would  employ  on  ordinary 
steel  work.  It  might  be  mentioned  here  that  when  working 
on  alloyed  and  high-carbon  steels,  the  filler-rod  generally 
contains  some  of  the  alloy  or  carbon  which  will  tend  to 
replace  that  destroyed  by  the  action  of  the  flame  in  the  origi- 
nal metal. 

(93)  In  welding  cast  steel  the  same  procedure  takes  place 
as  -previously  described  for  steel,  and  it  should  present  no 
real  difficulties  after  that  process  is  understood.  There  may 
be  more  sand,  oxide  and  other  impurities  present  on  account 
of  the  nature  of  the  metal,  but  these  can  all  be  worked  out 
if  plenty  of  heat  is  applied.  At  times,  when  working  in  steel, 
it  will  be  found  that  there  may  be  a  small  hole  develop  in 
the  center  of  the  weld  and  as  the  torch  is  worked  into  this 
hole  it  is  found  that  it  goes  down  a  short  distance  and  seem- 
ingly refuses  to  be  worked  out.  This  is  what  most  welders 
call  a  "  crater,"  and  is  caused  by  the  metal  at  the  bottom 
not  being  hot  enough  for  the  surrounding  melted  metal  to 
fuse  it.  When  found  they  should  be  removed  before  adding 
any  more  metal.  By  playing  the  torch  flame  around  and 
around  it,  so  that  the  heat  may  be  transmitted  to  the  bottom 
of  the  "  crater  "  and  it  brought  to  the  melting-point  like 
the  surrounding  metal  and  suddenly  jerking  the  torch  away, 


STEEL  WELDING  89 

it  will  disappear.  "  Craters  "  are  generally  formed  during 
the  first  part  of  the  weld,  especially  if  the  "  V  "  is  narrow, 
and  they  are  hard  to  handle  when  deep.  Under  no  circum- 
stances should  the  filler-rod  be  melted  into  them  in  trying  to 
make  them  disappear,  as  this  will  only  mean  covering  them 
over. 

(94)  Some  welders  find  that  hard  spots  develop  in  their 
welds  which  they  have  difficulty  in  overcoming,  and  it  is  a 
very  serious  handicap  when  the  weld  is  to  be  machined,  for 
ofttimes   it  will   break  very   expensive    tools    and   leave  a 
portion  of  a  drill  or  die  broken  off  in  the  metal.     It  is  prob- 
ably safe  to  say  that  the  principal  cause  of  hard  spots  in  steel 
welds  is  due  to  lack  of  heat.     This,  if  given  careful  thought 
and  consideration,  will  be  brought  home  forcibly  to  the  welder 
as  he  proceeds  in  his  work,  for  the  lapping  of  metals,  trapping 
of  oxides,   "  craters,"    too   rapid   cooling,   etc.,   may   all  be 
directly  attributed  to  a  lack  of  sufficient  heat.     If  the  metal  is 
in  a  molten  state,  all  impurities  will  be  brought  to  the  sur- 
face, for  they  are  bound  to  be  displaced  by  the  weight  of  the 
metal,  the  same  as  corks  in  a  barrel  will  float  to  the  top  if 
water  is  introduced.     The  water  in  this  case  has  a  greater 
specific  gravity  than  the  corks. 

(95)  In  welding  on  sheet  iron  and  steel,  many  operators 
will  find  that  they  have  more  difficulty  in  executing  a  suc- 
cessful  weld   than   on   slightly   heavier   work.     This   is    no 
doubt  due  to  the  thin  nature  of  the  work  and  the  ease  with 
which  it  may  be  burned  or  carbonized  if  the  operator  is  not 
alert.     When  working  on  such  material   a  very  small  filler- 
rod  is  used  if  thought  necessary  but  this  rod  must  be  as 
free  from  impurities  as  possible.     When  working  on  a  long 
seam  such  as  may  be  encountered  on  a  steel  tank,  it  will  be 
noticed  that  in  welding  from  one  end  along  the  seam  that  the 
metal  ahead  of  the  flame  will  tend  to  overlap  as  shown  in 
Fig.  61.     This  may  be  overcome  by  tacking  (that  is,  fusing 


90  OXY-ACETYLENE  WELDING  MANUAL 

the  metals  together),  at  various  points  before  starting  the 
weld,  or  the  parts  ahead  of  the  torch  can  be  separated  as  is 
shown  in  Fig.  62  and  held  this  way  by  using  a  wedge.  This 
is  moved  along  as  the  weld  advances  and  permits  the  edges 
to  close  together.  Another  method  used  by  manufacturers 
who  make  a  specialty  of  this  work  is  to  construct  a  jig  which 


FIG.  6 1. —The  Open  Ends  on  long  Steel  Welds  will  Overlap  as  the  Welding 
Progresses  if  Improperly  Started. 


FIG.  62. — Showing  how  Open  Ends  of  Steel  pieces  are  Spread  Slightly  to  Over- 
come Lapping  of  Ends  in  Making  Weld. 

clamps  the  ends  rigidly  and  they  are  welded  while  in  this 
position.  This  phenomenon  in  steel  welding  will  appear 
rather  strange  to  the  welder  who  has  had  some  experience  on 
thin  cast-iron  work,  such  as  oven  doors  and  the  like.  In 
these  he  found  that  as  his  weld  advanced,  the  welded  portion 
before  him  would  separate,  and  when  he  had  welded  about 


STEEL  WELDING 


91 


four  inches  or  so  it  would  be  necessary  for  him  to  jump  his 
flame  back  to  the  beginning  of  his  weld  and  heat  up  that 
portion,  in  order  to  close  up  the  cracks  before  him  previous 
to  his  continuing  the  work.  This  is  illustrated  in  Fig.  63. 
This  may  be  explained  by  the  fact  that  steel  is  a  very 
ductile  metal  and  when  it  is  fused,  the  expansion  is  taken 
care  of  internally  by  the  two  edges  combining.  Then,  in 
cooling,  the  metal  contracts,  an  action  much  more  rapid  in 
steel  than  in  cast  iron,  and  draws  the  edges  of  the  steel  plates 
past  each  other  so  that  they  overlap.  In  cast  iron,  which  is 


FIG.  63.— This  Illustration  Shows  how  the  Open  Ends  of  Thin  Cast-iron 
Pieces  Spread  apart  as  the  Weld  Progresses.  To  Close  the  Edges  to- 
gether, Jump  the  Torch  Flame  from  B  to  A;  as  A  heats  up,  B  Cools 
and  the  Lever-like  Action  Closes  the  Opening. 

rigid,  the  edges  are  expanded  by  the  fusion  of  the  metal  and 
this  space  is  then  filled  up  with  new  metal,  holding  the  edges 
apart.  As  the  weld  progresses  the  metal  ahead  of  the  torch 
is  pushing  out,  and  that  behind  is  cooling  off,  which  acts  as 
a  lever  on  each  side  to  open  up  the  unwelded  ends. 

(96)  To  weld  a  broken  automobile  frame  successfully 
the  body  of  the  car  should  be  raised  if  necessary,  to  keep  it 
from  burning  and  all  pipes,  wires  and  gasoline  leads  pro- 
tected with  a  covering  of  asbestos  paper.  Plenty  of  room 
should  be  allowed,  so  that  the  welder  may  have  easy  access 
to  the  break,  and  the  frame  should  be  jacked  up  on  both  sides 


92  OXY-ACETYLENE  WELDING  MANUAL 

of  the  break  until  the  frame  is  in  proper  alignment.  Then 
weld  the  crack  from  the  outside,  working  across  the  top, 
then  down  the  side  and  across  the  bottom,  reinforcing  a 
little  if  necessary  on  all  sides  but  the  bottom.  Then  repeat 
this  operation  on  the  inside,  reinforcing  at  all  points.  Then 
take  a  strip  of  steel  about  one-eighth  or  one-quarter  inch 
thick  and  six  or  eight  inches  long  and  as  wide  as  the  bottom 


FIG.  64. — A  Good  Method  of  Reinforcing  a  Weld  on  an  Automobile  Frame 
is  Here  Shown.  The  Patch  as  Pictured  Here  is  only  " Tacked  On."  It 
Should  be  Welded  Securely  to  the  Bottom  of  the  Frame  on  all  Four  of 
its  Edges. 

of  the  frame.  This  piece  should  be  welded  securely  to  the 
bottom  of  the  frame  with  the  former  break  in  the  middle  of 
the  strip.  A  cut  representing  this  job  is  shown  in  Fig.  64. 
By  this  method  the  frame  can  be  made  stronger  than  origi- 
nally. 

PART  THREE.— STEEL  WELDING 

(97)  ASIDE  from  the  difficulties  already  mentioned  in  steel 
welding,  there  are  many  others.  A  few  of  these  will  be  taken 
up  in  order  to  let  the  beginner  know  how  to  approach  the 
various  problems  which  may  confront  him.  But  in  no  wise 
is  this  to  be  considered  to  be  a  treatise  on  advanced  work.  Oft- 


STEEL    WELDING  93 

times  the  question  arises,  Can  springs  be  successfully  welded? 
Now,  while  springs  have  been  welded,  and  they  have  been 
tested  out  thoroughly,  yet  the  practice  of  spring  welding 
with  the  oxy-acetylene  flame  is  not  to  be  recommended. 
There  are  those  who  will  weld  leaf  springs,  such  as  are  found 
on  automobiles,  and  will  apply  rapid  blows  with  the  hammer, 
while  their  weld  is  still  in  a  heated  condition  and  then  plunge 
the  spring  in  water  or  oil  to  harden  it  and  the  weld.  A 
close  observer  will  readily  see  why  this  procedure  is  not 
correct.  Springs  of  this  nature  are  made  up  of  metal  which 
takes  a  uniform  hardening,  and  were  it  not  so  they  could  not 
be  considered  springs.  Now,  if  there  is  a  fracture  and  a 
foreign  metal,  which  under  no  circumstances  can  be  expected 
to  take  the  same  hardening  as  the  rest  of  the  spring,  is  intro- 
duced into  the  weld,  it  can  easily  be  seen  why  a  fusion  of  this 
kind  is  not  to  be  relied  upon.  If  it  were  possible  to  diagnose 
or  take  an  analysis  of  the  metal  in  the  spring  and  use  a  filler- 
rod  which,  after  being  acted  upon  by  the  flame,  would  come 
out  the  same  as  the  metal  in  the  spring,  then  some  success 
might  be  expected,  but  until  that  time,  welding  of  springs 
will  not  be  encouraged.  Unless  perchance  the  break  is  of 
such  a  nature  that  it  can  be  reinforced  readily  and  is  in 
such  a  position  that  a  resilient  quality  is  not  necessary. 

(98)  Work  on  crank-shafts  often  causes  perplexity  on  the 
part  of  the  beginner,  for  he  usually  hears  this  matter  discussed 
pro  and  con.  Crank-shafts  of  four  inches  in  diameter  can  be 
successfully  welded  with  the  oxy-acetylene  flame,  and  even 
larger,  if  correct  methods  are  employed.  There  are  many 
points  which  the  welder  considers  before  deciding  whether  a 
weld  of  this  nature  is  advisable.  Of  course  the  usability  of 
the  piece  after  it  has  been  welded  is  the  main  issue  when 
executing  any  kind  of  a  repair  job.  Now,  a  crank-shaft 
will  generally  break  in  either  of  two  ways;  by  some  external 
force,  such  as  a  connecting  rod  breaking  loose,  or  by  crystalli- 
zation, which  is  usually  due  to  fatigue.  Now,  in  the  latter 


94  OXY-ACETYLENE   WELDING   MANUAL 

case,  ofttimes  the  shaft  will  break  in  the  cheek  of  the  ''off- 
set," and  possibly  no  part  of  the  shaft  is  thrown  out  of  align- 
ment. When  such  is  the  case,  welding  is  usually  recommended 
and  the  shaft  may  be  brought  back  to  a  useful  state  in  very 
quick  order.  However,  in  the  former  case,  the  shaft  is  apt 
to  be  sprung,  and  while  it  could  be  welded,  the  machine 
work  necessary  to  restore  it  to  normal  requires  much  time, 
and  it  has  been  known,  where  after  spending  a  matter  of 
days  in  trying  to  get  proper  alignments,  work  was  scrapped  as 
useless.  So  it  is  entirely  up  to  the  welder  in  work  of  this 


FIG.  65.— Building  Up  Worn  Shafts. 

kind  to  determine  whether  the  job  is  worth  while  or  not. 
There  are  certain  parts  of  a  crank-shaft  upon  which  welding 
work  can  be  done  with  a  marked  degree  of  success,  such 
as  building  up  worn  bearings  and  the  like.  In  doing  work 
of  this  kind  it  is  recommended  that  the  welder  fuse  his  metal 
in  a  line  parallel  to  the  center  line  of  the  bearing,  seeing  to 
it  that  he  has  a  perfect  fusion  between  the  surface  of  the  bear- 
ing and  the  metal  he  is  fusing  and  adding  plenty  of  metal, 
to  insure  enough  being  used,  so  that  no  low  spots  will  show 


STEEL  WELDING 


95 


up  when  it  is  machined.  It  is  considered  that  by  adding  the 
metal  as  suggested  the  welder  will  hold  his  heat  much  better 
than  if  he  attempted  revolving  the  shaft  continually.  Fig. 
65  will  show  the  method  here  outlined  in  a  very  clear  way. 

(99)  When  working  on  shafts  the  welder  will  encounter 
such  articles  as  automobile  propeller  shafts  and  rear  axles, 
which  generally  break  adjoining  the  square  ends.  He  will 
no  doubt  wonder  whether  it  is  advisable  to  weld  this  square 
end  back  on,  or  whether  to  try  and  build  up  the  shaft  the 
desired  length.  Undoubtedly  the  point  of  fracture  is  the 


FIG.  66.— Shaft  Broken  at  End  of  Square  Shank,  its  Weakest  Point. 


FIG.  67. — Broken  Part  of  Shaft  Removed  and  New  Piece  Added,  thereby 
Moving  the  Weld  away  from  the  Weak  Part. 

weakest  portion  of  the  entire  shaft,  else  it  would  not  break 
there.  The  execution  of  a  weld  at  this  point  where  no 
additional  metal  can  be  added  or  any  means  of  reinforcing 
used  is  not  to  be  recommended.  Fig.  66  will  show  the  problem 
which  confronts  the  welder,  and  Fig.  67  the  suggested  means 
of  overcoming  the  difficulty.  By  removing  about  four  inches 
from  the  broken  end  of  the  shaft  and  adding  a  new  piece, 
about  ten  inches  long,  of  the  same  diameter,  the  weld  will 
be  removed  from  the  weak  point;  a  heavier  weld  can  be 
made,  and  the  end  can  be  machined  off  to  the  desired  size. 
This  procedure  is  recommended  on  all  jobs  of  like  nature. 


96  OXY-ACETYLENE  WELDING  MANUAL 

(100)  Occasionally  case-hardened  ring  gears  are  brought 
to  the  welder  to  have  teeth  built  up  or  new  ones  added,  and 
although  the  welder  must  realize  that  the  hardening  is  de- 
stroyed by  the  action  of  the  flame,  yet  he  does  not  under- 
stand why  it  is  necessary  to  reharden  the  gear.  A  little 
thought  on  this  subject  will  make  him  appreciate  the  fact  that 
if  he  destroys  certain  properties  in  metal  which  have  been 
introduced  for  a  reason,  these  must  be  replaced  if  he  would 
bring  the  job  back  to  normal.  It  would  be  like  heating  up  a 
tempered  lathe  tool,  or  cold  chisel  for  that  matter,  and  try- 
ing to  use  it  before  it  had  been  retempered.  Therefore  if 


FIG.  68. — When  Welding  a  Small  Section  to  a  Larger  One,  the  Flame  of  the 
Torch  is  Directed  toward  the  Heavier  of  the  Two. 

hardening  or  temper  is  destroyed  by  the  flame  it  must  be 
restored. 

(101)  If  a  weld  were  to  break,  it  would  be  necessary  for 
the  welder  to  remove  all  metal  added  in  the  first  weld  before 
attempting  to  reweld.     This  is  true  of  his  own  work  as  well 
as  that  of  others  which  he  may  be  called  upon  to  do.     For 
no  matter  how  good  the  surface  may  appear,  without  a  solid 
foundation  no  weld  is  of  any  value,  and  unless  he  clears  out 
all  of  the  old  metal  he  cannot  be  sure  of  the  work.     This  will 
apply  not  only  to  steel  work,  but  to  all  metals,  and  it  is  a  point 
which  should  be  borne  in  mind. 

(102)  At  times  there  are  jobs  come  up  in  which  one  piece 


STEEL  WELDING  97 

of  work  is  to  be  fused  to  another  which  is  much  larger,  and 
will  absorb  much  more  heat  during  the  weld.  When  hand- 
ling such  work,  it  will  be  necessary  to  play  the  torch  upon  the 
larger  piece  most  of  the  time,  as  shown  in  Fig.  68,  in  order 
to  bring  both  pieces  to  a  fusion  point  at  the  same  time  and 
keep  them  in  that  condition. 

(103)  Once  in  a  while  it  will  be  necessary  for  a  welder  to 
fuse  cast  iron  to  steel  or  vice  versa,  and  the  question  will  arise 
as  to  which  filler-rod  he  will  use.     It  has  been  found  that 
a  cast-iron  filler-rod  can  be  used  with  success  and  of  course 
when  using  a  cast-iron  filler-rod,  a  cast-iron  flux  will  be  neces- 
sary.    Work  of  this  nature  is  not  very  frequent. 

PART  FOUR.— STEEL  WELDING 

(104)  WHEN  steel  is  in  a  melted  condition,  it  seems  to 
be  in  a  very  susceptible  state.     It  appears  to  absorb  gases, 
and  with  constant  working  an  oxidation  is  in  evidence  which 
materially  effects  the  strength  of  the  metal.)    When  working 
o»  vanadium  and  other  alloyed  steels,  if  kept  in  a  molten 
condition  too  long,  many  of  their  principal  characteristics  are 
destroyed.!   For  this  reason  it  is  advisable  to  execute  steel 
welds  just  as  rapidly  as  possible.     While  this  is  true  of  most 
work,  it  is  especially  to  be  emphasized  on  steel.     To  assist 
the  welder  in  executing  welds  on  large  steel  castings,  the  pieces 
are  generally  preheated,  so  that  the  work  will  take  less  time, 
be  more  successful,   and  save  both  oxygen  and  acetylene. 
When  working  on  preheated  jobs,  in  order  to  get  the  desired 
angle  on  the  filler-rod  so  the  welder  may  use  it  without  dis- 
comfort, a  light  heat  is  played  on  the  filler-rod,  a  matter  of 
six  or  eight  inches  from  the  end  being  fused  and  then  bent 
to  an  angle  of  90  degrees,  so  that .  the  operator  may  hold 
the  rod  at  some  distance  from  his  work  and  still  introduce 
it  in  the  manner  he  desires.     Some  operators  weld  their  cast- 


98  OXY-ACETYLENE  WELDING  MANUAL 

iron  filler-rods  together,  to  get  the  desired  angle  as  shown  in 
Fig.  69,  but  this  is  not  as  common  as  the  steel  method, 
probably  because  cast  iron  will  not  bend  and  it  requires  some 
time  to  weld  the  rods  together  in  this  manner. 

(105)  In  some  parts  of  the  country  boiler  flues  are 
acted  upon  and  eaten  away  by  the  impure  water  used,  and 
when  high  prices  prevail,  re  tipping  is  generally  resorted  to.  A 
simple  method  in  which  they  can  be  satisfactorily  and  cheaply 


FIG.  69. — Kinks  for  Handling  "Filler-rod"  on  Large  Work  to  Remove  Welder's 
Hand  away  from  Heat  of  Flame. 

(a)  shows  how  the  steel  "Filler-rod"   is  heated  by  the  torch  flame  about  6  inches  from  the 
end  and  bent  to  the  angle  desired. 

(b)  illustrates  how  cast  "Filler-rods"  are  handled.      Since  they  will  not  bend,  they  are  welded 
in  the  T  shape  shown.     First  one  side  is  used  in  fusing,  and  then  the  other. 

done  is  as  follows:  Cut  off  the  poor  end  until  solid  metal 
is  reached,  with  a  pipe  cutter,  which  will  tend  to  "  V  "  the 
work  as  it  cuts  and  at  the  same  time  will  squeeze  the  edge  of 
the  pipe  in.  After  cutting,  this  end  of  the  flue  is  placed  on 
the  horn  of  an  anvil  and  the  burr  on  the  inside,  which  has  been 
made  by  the  cutter,  is  flattened  out.  It  is  very  important  that 
the  flue  be  of  the  same  size  throughout  in  order  to  permit 
its  being  cleaned.  It  is  then  placed  in  "  V  "  blocks  or  a 


STEEL  WELDING  99 

trough,  made  of  angle  iron,  such  as  shown  in  Fig.  70,  and  the 
new  end  which  has  been  prepared  in  much  the  same  way 
is  placed  in  the  position  shown  in  A  in  the  same  figure. 
The  piece  is  tacked  on  at  two  or  more  spots  and  then  laid 
aside  until  the  whole  set  of  flues  has  been  prepared  in  this 
manner.  Then  they  are  replaced  in  the  trough  and  welded, 
one  after  another,  being  turned  at  one  end  by  a  helper,  thus 
allowing  the  welder  to  do  continuous  work.  Care  must 
be  taken  at  all  times  that  perfect  fusion  takes  place  between 
the  flue  proper  and  the  piece  being  added,  yet  at  no  time 
should  the  metal  be  allowed  to  run  on  the  inside  of  the  pipe. 
More  metal  can  be  added  than  is  really  necessary  and  can 


%^^ 

FIG.    70. — Showing    a  Simple    Way    to    "Line-up"    Flues  when  Retipping. 
B  Represents  the  old  Flue,  and  A  the  New  Piece  to  be  Added. 


later  be  dressed  down  on  a  grinding  wheel  to  the  desired  size, 
which  must  be  such  that  replacement  of  the  flue  can  be  made. 
Various-sized  pipes  can  be  welded  in  much  the  same  way 
where  no  reducers  are  obtainable,  the  only  change  being 
that  there  must  be  a  step  made  in  the  trough  which  will 
permit  the  various-sized  pipes  being  lined  up  correctly. 
Jigs  for  the  speeding  up  of  manufactured  articles  which  are 
to  be  welded  are  always  being  brought  out  by  the  ingenious 
workman  and  are  to  be  encouraged  whenever  possible. 

(106)  In  the  repair  of  boilers  many  a  feasible  job  has 


100 


OXY-ACETYLENE   WELDING   MANUAL 


been  given  up  as  impossible  by  the  unthinking  welder. 
Cracks  have  been  found  in  fire-box  sheets  around  the  stay- 
bolts  which,  as  soon  as  they  are  touched  with  the  flame, 
seem  to  run  and  keep  running.  They  really  discourage  those 
who  are  not  familiar  with  this  class  of  work.  Many  such 
welds  have  been  executed  and  are  apparently  all  right  until 
tested,  when  they  give  way  and  make  the  job  worse  than  it 


(Courtesy  of  the  Oxweld  Acetylene  Co.) 
FIG.  71.— Welded  Cracks  between  Staybolts. 

was  previously.  The  trouble  is  in  these  instances  that  the 
welder  has  made  no  provision  for  contraction  and  while 
the  job  might  appear  to  be  successful,  yet  the  internal  strains 
exerted  will  not  show  themselves  at  the  test.  Many  boiler 


STEEL   WELDIN0: 


101 


shops  have  found  that  the  flat  patch  is  not  to  be  relied  upon 
and  when  a  crack  is  found  between  two  stay-bolt  holes, 
such  as  shown  in  Fig.  72,  a  round  hole  is  cut  as  shown  by  the 
dotted  line.  A  circular  plate  is  then  cut  slightly  larger  than 
this  hole  and  after  being  brought  to  a  red  heat,  it  is  bellied 
by  the  use  of  a  hammer  or  a  set  of  dies,  so  that  it  assumes 


FIG.  72. — A  Crack  between  the  Staybolts  in  a  Boiler  should  be  Cut  Out  as 
Shown  by  the  Dotted  Line,  to  Prepare  it  for  a  "Dished"  Patch. 


FIG.  73.— A  "Dished"  Patch. 

the  shape  of  a  saucer  and  is  called  by  many  a  "  dished  " 
patch.     Some  idea  may  be  had  of  such  a  patch  from  Fig.  73. 

(107)  The  patch  is  placed  in  the  sheet  with  the  concave 
side  toward  the  operator  and  should  be  securely  welded  in 
place,  adding  as  little  metal  for  reinforcement  as  possible, 


pK)2  OXY-ACETVLENE  WELDING  MANUAL 

but  seeing  to  it  that  a  perfect  fusion  is  made  between  the 
patch  and  the  sheet  all  the  way  through.  As  soon  as  the 
weld  is  complete  the  torch  is  played  upon  the  high  part  of  the 
patch,  which  is  protruding,  and  as  the  weld  cools  off,  sharp 
quick  blows  can  be  applied  to  the  center  of  the  patch,  which 
should  be  kept  in  a  heated  condition  until  it  is  nearly  flat. 
This  will  take  care  of  any  contraction  that  might  set  up  and 
is  a  very  good  way  of  handling  patches  which  do  not  exceed 
six  or  eight  inches  in  diameter. 

(108)  A  "  corrugated  "  patch  has  been  brought  out  more 
recently  than  the  "  dished  "  patch,  and  as  its  name  would 


FIG.  74.— A  "Corrugated"  Patch. 

indicate,  it  has  corrugations  around  at  least  three  of  its  sides. 
While  a  "  dished  "  patch  is  limited  in  its  scope  and  cannot 
be  applied  to  square  holes  unless  the  square  holes  be  cut 
round,  the  "  corrugated  "  patch  knows  absolutely  no  limits 
as  to  size  or  shape.  While  its  preparation  is  probably  more 
difficult,  yet  its  purpose  is  the  same,  that  is,  to  take  care  of 
the  contraction  which  takes  place  in  sheets  of  metal  where 
heat  has  been  introduced.  To  prepare  a  "corrugated" 
patch,  a  piece  of  metal  which  is  somewhat  larger  than  the 
hole  is  taken  and  the  corrugation  is  made  by  placing  two  rods 
on  one  side  and  somewhat  separated  and  between  them  on  the 
other  side  another  rod.  With  this  section  of  the  patch 
heated  to  a  red  heat,  a  drop  hammer  is  played  upon  it  and 


STEEL  WELDING  103 

a  corrugation  effected.  Or  an  easier  method  is  by  the  use  of 
specially  prepared  dies,  which  will  turn  out  a  patch  in  quick 
order.  It  must  be  remembered  that  while  the  patch  shown  in 
Fig.  74  is  only  for  a  very  simple  job,  which  is  rectangular 
in  shape,  yet  "  L  "  shaped  patches  can  be  prepared  and 
handled  in  the  same  manner.  When  the  corrugation  has  been 
introduced  into  the  patch,  the  latter  is  cut  so  that  it  will 
fit  the  hole,  and  it  is  tacked  in  position  with  the  bellied 
sides  out.  The  method  used  in  applying  a  patch  of  this  kind 
is  to  weld  the  uncorrugated  side,  then  start  up  the  corrugated 
side  and  weld  for  two  or  three  inches,  then  play  the  torch 
upon  the  corrugation,  adjoining  the  part  welded,  and  slightly 
hammer  to  assist  in  the  expansion  of  the  same;  then  return 
to  the  weld,  continuing  it  until  the  corrugation  can  again  be 
played  upon.  By  doing  this,  when  finished  the  patch  will 
be  flat  and  no  signs  of  the  corrugations  will  be  shown.  While 
many  patches  of  this  nature  are  in  use  giving  the  very  best 
service,  the  welder  who  looks  upon  the  finished  job  cannot 
tell  how  it  has  been  accomplished. 

(109)  While  the  methods  here  given  seem  only  to  apply 
to  boiler  work,  they  are  not  so  restricted  and  can  be  applied 
to  tanks  and  various  vessels  with  success.  However,  when 
welding  on  tanks  which  have  contained  inflammable  gases  or 
gasoline  the  welder  is  cautioned  to  take  every  measure  to 
safeguard  himself,  and  while  it  is  known  that  much  work  is 
being  done  on  such  jobs,  it  is  not  recommended  and  in  fact 
quite  the  contrary.  It  is  true  that  there  are  such  methods  as 
filling  the  containers  with  water;  cleansing  with  live  steam, 
and  so  forth,  but  the  cautious  man  will  refrain  from  working 
on  these  vessels  even  though  such  measures  have  been 
taken.  Gasoline  has  a  faculty  of  penetrating  the  pores 
of  metallic  surfaces,  and  although  these  vessels  have  been 
emptied  and  have  remained  so  a  matter  of  a  year,  the  gaso- 
line is  still  present  to  some  extent,  as  is  evidenced  by  the 


104  OXY-ACETYLENE  WELDING  MANUAL 

fact  that  as  soon  as  heat  is  applied  and  the  molecules  of  the 
metal  are  expanded,  the  gas  is  released  in  sufficient  quantities 
to  cause  an  explosion.  This  is  not  in  one  instance  only, 
but  in  many,  so  it  has  been  thought  best  to  discourage  any 
welding  work  on  vessels  which  have  contained  gasoline  at 
any  time. 

(no)  While  it  is  possible  to  weld  cast  iron  on  the  vertical, 
by  the  use  of  carbon  blocks  and  so  forth,  the  same  kind  of 
work  can  be  accomplished  on  steel  with  much  ease,  without 
the  use  of  any  blocks,  or  materials  other  than  the  filler-rod 


FIG.  75. — Working  a  Vertical  Weld  on  Steel,  from  the  Top  Down. 

and  the  welding  torch.  There  are  two  methods  of  handling 
vertical  welds;  welding  from  the  top  down,  or  starting  from 
the  bottom  and  working  up.  The  former  seems  to  be  con- 
demned by  those  who  have  never  tried  it,  on  account  of  the 
carelessness  which  is  apt  to  be  used  on  work  of  this  kind.  How- 
ever, for  the  beginner,  it  is  thought  advisable  to  teach  this 
method,  as  there  are  many  places  where  it  can  be  used  ad- 
vantageously. The  metal  at  the  top  of  the  seam,  such  as  a 
broken  automobile  frame,  or  the  like,  is  brought  to  a  molten 
state  and  held  there,  not  only  by  the  velocity  of  the  flame, 
but  also  by  the  filler-rod,  as  is  shown  in  Fig.  75.  With  the 


STEEL  WELDING  105 

choosing  of  a  tip  of  the  correct  size,  the  melted  metal  can 
be  held  under  control  with  much  ease,  after  a  little  practice, 
and  it  is  allowed  to  descend  as  soon  as  the  metal  below  it 
is  in  the  proper  shape  for  fusion.  The  filler-rod  is  added 
continually,  for  it  is  never  lifted  out  of  the  molten  metal, 
merely  stirred  a  little  from  side  to  side  as  it  descends.  None 
of  the  melted  metal  is  allowed  to  precede  the  flame,  and  at  all 
times  the  operator  can  see  whether  the  edges  to  be  fused  are 
at  the  right  heat.  As  soon  as  the  bottom  is  reached,  the  weld 
can  again  be  gone  over  if  it  is  not  thought  strong  enough, 
and  reiniorced  as  much  as  desired.  As  soon  as  the  operator 
is  familiar  with  this  method,  he  will  find  that  much  more 
speed  can  be  developed,  less  filler-rod  lost  and  less  lapping 
done  than  by  building  up  from  the  bottom. 

(in)  In  welding  over  head  there  is  a  tendency  on  the 
part  of  most  welders  to  avoid  the  use  of  enough  heat  to  bring 
their  metal  to  a  molten  state,  for  fear  that  it  will  drop  upon 
them.  It  must  be  remembered  thai  lack  of  heat  means  poor 
welds  and  that  the  metal  must  be  in  a  molten  condition  when- 
ever the  weld  is  to  be  made.  As  soon  as  a  little  practice  is 
given  to  this  kind  of  work,  the  welder  will  see  that  the  melted 
metal  can  assume  some  proportions  without  dropping  off, 
despite  its  weight.  It  has  probably  been  noticed  that  on 
"  sweating  "  water  tanks  drops  of  water  accumulate  on  the 
bottom  of  the  tank  and  do  not  fall  off.  It  is  the  same  sort 
of  problem  in  the  case  of  melted  steel.  The  adhesion  of  the 
molecules  and  the  surface  tension  are  the  forces  that  keep  the 
metal  from  dropping. 


CHAPTER  VIII 
BRASS  WELDING 

(112)  IT  is  difficult  for  the  beginner   to  accustom  him- 
self to  brass  welding,  especially  on  large  work.     While  he 
has  been  taught  to  believe  that  brass  has  a  much  lower 
melting-point  than  iron  or  steel,  yet  when  he  comes  face  to 
face  with  the  actual  problem  of  melting  it,  he  will  find  that 
it  is  necessary  to  hold  his  flame  in  contact  with  his  piece  much 
longer,  on  brass  work  than  on  either  of  the  other  two,  before 
the  melting  point  is  reached.     This  can  be  accounted  for  by 
the   great   conductivity   of  brass.     On   cast  iron   and   steel 
the  heat  was  rather  local,  but  on  brass  work  it  is  transmitted 
to  all  parts  of  the  piece  as  rapidly  as  it  is  introduced,  and  this 
absorbing  process  continues  until  practically  the  entire  piece 
is  near  the  melting  point. 

(113)  Brass  has  for  its  base,  copper  to  which  an  alloy 
of  zinc  has  been  added.     Now  the  most  difficult  part  of  fusing 
brass  work,  is  to  add  more  metal  from  the  filler-rod  to  the 
parts  which  are  to  be  fused,  without  burning  up  any  more 
of  the  alloy,  than  is  absolutely  necessary.     Seeing  that  the 
copper  and  zinc  have  different  melting  points,  it  is  a  very 
difficult  feat  and  requires  considerable  practice.     Much  of 
this  trouble  can  be  eliminated  by  the  use  of  a  filler-rod  which 
has  the  correct  proportion  of  alloy  added,  so  that  it  may  take 
care  of  and  replace  any  that  has  been  destroyed  by  the  flame. 

(114)  Brass  work  is  "  V-ed  "  out  when  welding  is  to  be 
done,  in  practically  the  same  way  as  cast  iron.     Only  under 
no  circumstances  should  the  ends  of  the  parts  be  burned 

106 


BRASS  WELDING  107 

off,  when  "  V-ing,"  as  the  heavy  oxide  which  is  deposited 
on  the  remaining  metal  is  very  hard  to  combat  with  the  weld- 
ing flame.  The  ends  of  the  work  are  brought  to  a  red  heat 
with  the  flame  that  is  slightly  carbonizing.  This  is  held 
directly  in  contact  with  the  work  during  the  preheating 
stages,  in  much  the  same  manner  as  on  cast  iron,  and  a  small 
layer  of  carbon  may  be  seen  to  accumulate  around  the  weld. 
Now,  in  theory,  this  would  seem  the  worst  thing  possible  to 
have  present,  but  in  practice  a  small  quantity  of  this  soot 
acts  as  an  aid  in  making  the  weld,  besides  making  the  flame 
less  intense,  which  saves  much  of  the  alloy,  from  being 
burned  when  the  fusion  occurs.  When  the  ends  have  become 
red  hot,  the  same  procedure  is  used  as  in  working  steel, 
except  that  the  torch  is  given  a  slightly  greater  angle  and  a 
brass  flux  is  used. 

(115)  Contrary  to  most  authorities  we  find  that  an 
abundance  of  good  flux  is  desirable  on  brass  work  and  that 
it  is  almost  impossible  to  use  too  much.  It  is  desirable 
to  use  only  the  best  welding  fluxes,  for  the  best  welds  are 
to  be  insured  only  under  ideal  conditions.  If  a  welder  were 
to  run  short  of  flux,  however,  he  might  use  powdered  borax 
of  the  20  Mule  Team  variety,  to  tide  him  over  until  he  could 
get  a  new  supply.  The  flux  is  added  in  the  same  way  as  the 
cast-iron  flux,  that  is,  by  dipping  the  heated  end  of  the  filler- 
rod  into  the  flux  container.  Enough  will  adhere,  and  when 
added  will  clear  up  the  metal  in  the  vicinity  of  the  weld.  It 
should  be  added  as  often  as  a  welder  notices  his  metal  needs 
cleaning  and  this  will  vary  depending  upon  whether  there  is  a 
slow  or  rapid  worker  behind  the  torch.  A  man  must  use 
his  own  judgment  in  cases  of  this  kind.  Remember  that 
the  flux  is  a  cleaning  agent  and  if  the  surface  is  clean,  no 
additional  flux  is  necessary,  but  if  the  contrary  is  true,  that 
is,  if  the  surface  is  full  of  oxide  and  the  filler  refuses  to  flow 
easily,  flux  is  necessary  and  should  be  added. 


108  OXY-ACETYLENE  WELDING  MANUAL 

(116)  During  the  welding,  dense  white  fumes  will  come 
from  the  fusing  brass.  This  is  the  burning  out  of  the  alloy, 
that  is,  the  zinc.  These  fumes  are  injurious  to  the  welder  and 
should  be  avoided,  if  possible,  by  proper  ventilation.  The 
use  of  a  proper  filler-rod  and  rapid  work  will  largely  tend  to 
overcome  the  presence  of  these  fumes,  but  if  the  operator 
is  very  slow,  they  will  appear,  and  are  followed  by  a  porous 
and  brittle  weld,  which  if  broken  afterwards  will  show  a 
large  number  of  blow  holes.  The  most  difficult  part  of  brass 
welding  as  a  whole  is  to  add  the  filler-rod,  being  certain  of  a 
fusion,  without  burning  out  the  zinc.  When  brass  is  in  a 
heated  condition,  it  is  very  fragile  and  will  crack  readily 
if  disturbed.  All  precautions  should  be  taken  to  see  that  no 
sudden  jarring  is  given  the  piece  until  the  weld  has  completely 
set.  When  this  work  is  done  many  welders  plunge  their  work 
in  water,  in  an  effort  to  make  it  more  ductile  and  easier  to 
machine.  While  this,  of  course,  is  condemned  by  theorists 
and  rightly  so,  in  practice  there  seems  to  be  no  injury  results. 


CHAPTER  IX 
PART  ONE.— ALUMINUM  WELDING 

(117)  So  far  as  the  actual  fusion  of  aluminum  is  con- 
cerned, it  is  probably  more  easily  learned  than  any  other 
metal,  but  on  account  of.  the  rapid  conductivity  of  heat  and 
the  loss  of  most  of  its  strength  when  heated,  aluminum  has 
caused  much  concern  among  oxy-acetylene  welders. 

(118)  There  are  two  methods  used  in  welding  aluminum, 
the    flux    method    and    the    puddle    method.     The    puddle 
system  gets  its  name  from  the  use  of  a  puddle  stick  or  spoon- 
like  rod  which  is  used  to  stir  the  metal  together,  and  is  very 
satisfactorily  used  on  all  cast  aluminum.    The  flux  method  is 
applied  to  both  cast  and  sheet  aluminum  and  it  is  so-called 
because  a  flux  is  used  to  break  up  the  oxide  along  the  line 
of   weld.     The   discussion    to   follow   applies   only    to   cast 
aluminum.     It  is  in  this  metal  that  most  interest  is  centered, 
as  the  welding  of  sheet  aluminum,  such  as  is  found  in  auto- 
mobile bodies  and  some  cooking  utensils,  is  not  encountered 
in  the  ordinary  run  of  work. 

(119)  When  working  with  the  flux  method  about  the  same 
sized  tip  is  used  as  when  working  on  cast  iron.     This  is  applied 
to  the  line  of  weld  and  held  there  until  the  oxide  on  the  sur- 
face commences  to  wrinkle  and  small  globules  of  a  mercury- 
like  appearance  form  on  the  surface.     When  heat  is  intro- 
duced in  aluminum  it  is  transmitted  throughout  the  piece 
in  the.  same  manner  as  occurs  in  copper  and  brass,  therefore 
it  will  require  much  more  time  to  heat  the  work  than  the  same 
sized  piece  of  cast  iron  or  steel.     As  soon  as  the  weld  assumes 

109 


110 


OXY-ACETYLENE  WELDING  MANUAL 


1 


ALUMINUM  WELDING  111 

the  condition  mentioned,  fast  work  is  necessary  or  the  metal 
will  collapse,  for  it  loses  most  of  its  strength  when  heated  to 
this  condition.  The  end  of  the  filler-rod  bearing  the  flux 
is  brought  down  on  the  metal  and  immediately  the  surfaces 
will  clear  up  and  run  together,  like  so  much  mercury.  The 
torch  is  instantly  jerked  away  and  applied  farther  along  the 
weld.  The  theory  of  this  reaction  is  that  the  heavy  alumi- 
num oxide  is  the  only  thing  which  prevents  the  metal  flowing 
together  when  heated,  and  as  soon  as  the  flux  is  introduced 
this  oxide  will  be  destroyed  along  the  line  of  weld  and  a  fusion 
of  the  metal  effected.  This  actually  takes  place,  providing 
enough  heat  has  been  introduced  to  permit  this  reaction  to 
penetrate  the  depth  of  the  weld.  The  flux  contains  the 
chemicals  necessary  to  cause  this  reaction  if  the  metal  is 
in  the  right  condition.  There  are  many  welders  who  do  not 
use  sufficient  heat  and  blame  the  faulty  results  upon  the 
flux.  On  the  other  hand,  there  are  many  fluxes  which  are 
absolutely  useless  in  performing  a  function  of  this  kind. 
The  chemicals  necessary  in  compounding  a  good  flux  for 
this  class  of  work  are  expensive  and  therefore  this  flux  cannot 
be  procured  at  a  low  price.  When  the  weld  is  finished  and 
cooled  the  surface  should  be  scrubbed  with  soap  and  water 
to  remove  all  traces  of  the  flux,  otherwise  a  corrosion  may 
occur  a  month  or  so  afterwards,  and  while  it  may  not  affect 
the  weld  in  any  degree,  the  owner  of  the  piece  may  not  be 
pleased  at  the  sight.  It  is  therefore  advisable  to  remove  all 
traces  of  flux  used  on  aluminum  work. 

(120)  The  puddle  system  differs  from  that  of  the  flux, 
insomuch  that  when  the  metal  has  been  brought  to  the 
same  heat,  where  the  flux  has  been  applied  it  will  be  found 
that  the  metal  is  really  in  a  pasty  condition.  It  can  be 
stirred  together  and  the  break  entirely  eliminated  by  the  use 
of  a  puddle  stick,  either  of  a  pointed  or  a  flat  spoon-shape 
design,  as  shown  in  Fig.  77.  During  this  puddling  stage, 


112  OXY-ACETYLENE  WELDING  MANUAL 

the  torch  is  usually  held  in  the  left  hand  with  the  flame  some 
distance  away  from  the  work,  only  introducing  enough  heat 
to  keep  the  puddle  pasty.  The  puddle  stick  is  handled 
by  the  right  hand  and  when  extra  metal  is  needed  the  puddle 
stick  is  laid  aside  and  the  aluminum  filler-rod  is  picked  up 
and  worked  into  the  weld.  When  sufficient  metal  has  been 
added  the  puddle  stick  again  comes  into  play  and  can  be 
used  in  stirring  the  metal  together  and  finishing  it  off  in  the 
desired  manner.  Reinforcing  the  weld  will  apply  to  aluminum 
the  same  as  every  other  metal,  and  a  very  neat  job  can  be 
made  after  a  little  practice  with  the  puddle  stick.  At  times 


0 


FIG.  77. — "Puddle-sticks"  for  Welding  Aluminum. 

some  of  the  aluminum  may  adhere  to  the  stick,  which  is  made 
from  a  quarter-inch  piece  of  steel  filler-rod,  but  this  can  be 
removed  by  scraping  it  upon  the  fire  bricks  which  should  be 
in  the  vicinity  of  the  weld. 

(121)  There  are  two  kinds  of  filler-rods  used  in  aluminum 
welding.  Both  are  aluminum,  but  one  is  cast  and  the  other 
is  9  drawn  rod.  This  same  difference  will  also  be  noticed  in 
bronze  filler-rods,  and  there  has  been  much  discussion  as  to 
which  is  the  desirable  one  to  use.  Neither  of  them  is  sup- 
posed to  be  100  per  cent  pure  aluminum,  as  such  a  filler-rod 
does  not  give  the  desired  results  under  the  action  of  the 


ALUMINUM  WELDING  113 

flame.  A  matter  of  from  90  to  95  per  cent  aluminum,  with 
5  per  cent  to  10  per  cent  of  copper  present  as  an  alloy,  is  found 
to  make  a  stronger  and  more  successful  weld.  It  is  recom- 
mended, if  possible,  to  use  the  drawn  rods  whenever  avail- 
able; for  a  weld  at  best  is  only  a  casting,  and  if  this  casting 
can  be  made  from  virgin  metal,  rather  than  recast  from  metal 
which  has  been  cast  many  times  and  the  contents  not  known, 
it  is  thought  that  the  results  will  be  far  more  satisfactory. 
A  weld  made  with  such  a  filler-rod,  care  being  taken  to  work 
out  the  oxides,  will  compare  very  favorably  with  the  strength 
of  the  original  metal  and  in  many  instances  a  reinforcement 
will  make  it  much  stronger. 

(122)  To  combine  the  two  methods  of  welding  aluminum 
is  not  recommended.     If  the  flux  were  stirred  up  inside  the 
weld  with  a  puddle  stick  an  unsatisfactory  weld  would  result, 
so  they  are  to  be  kept  entirely  separate.     It  is  not  necessary 
to  "  V  "  out  aluminum  for  the  same  reason  as  other  metals 
are  "  V-ed  "  out.     When  it  is  in  workable  condition  it  can  be 
puddled  and  stirred  about  as  desired.     It  is  well,  however, 
to  "  V"  out  slightly  for  the  sake  of  marking  the  line  of  weld. 
When  aluminum  is  heated  up,  the  expansion  which  occurs 
may  close  up  the  crack,  which  was  previously  quite  visible, 
in  such  a  manner  that  it  cannot  be  located  without  much 
loss   of   time.     Ordinary   chalk   or   soapstone,    if   available, 
may  be  used  to  mark  any  preheated  work,  but  the  use  of  a 
chisel  along  the  line  of  weld  is  the  most  reliable  method. 

PART  Two.— ALUMINUM  WELDING 

(123)  IT  will  be  noticed,  when  welding  aluminum,  that 
bright  surfaces  will  oxidize  immediately  when  exposed  to  the 
air.     This  action  occurs  perhaps  faster  on  aluminum  than  on 
any  other  metal.     With  this  oxide  or  scale  present  the  metal 
will  not  run  together  nor  fuse,  no  matter  how  much  heat  is 


114  OXY-ACETYLENE  WELDING  MANUAL 

applied.  The  metal  may  be  molten  on  each  side  of  an 
oxidized  crack  and  at  times  will  cause  the  line  of  fracture  to 
even  float,  but  if  the  oxide  is  not  destroyed  the  metal  will 
not  fuse.  As  has  been  noted  previously,  two  methods  are 
used  to  destroy  this  oxide,  namely,  the  flux  method  and  the 
puddle  system.  On  account  of  this  exceedingly  rapid  oxida- 
tion, it  will  be  found  to  the  operator's  advantage  to  complete 
his  aluminum  welds  as  quickly  as  possible  in  order  that  he 
will  have  less  of  this  oxide  to  combat.  It  will  be  found  in 
using  the  puddle  system  that  greater  haste  can  be  made  by 
using  the  torch  in  the  left  hand,  leaving  the  right  free  to  do 
the  puddling  and  to  add  whatever  metal  is  necessary.  In 
this  method  most  of  the  success  depends  upon  the  operator's 
skill  in  handling  his  puddle  stick  and  puddling  in  additional 
metal.  Generally  the  right  hand  can  do  this  more  rapidly 
than  the  left. 

(124)  It  is  well  to  learn  how  to  make  a  successful  weld 
from  one  side  of  the  metal  only,  and  while  this  will  apply 
to    all   metals,    it   is    especially    advantageous    in    working 
aluminum.     Where  a  small  layer  of  metal  has  been  added 
to  one  side  of  an  aluminum  job,  such  as  a  crank  case,  and  it 
does  not  penetrate  the  entire  thickness  of  the  metal,  when  the 
other  side  is  turned,  and  the  flame  applied  to  it,  a  difference 
in  temperature  and  the  loss  of  strength  in  this  metal  when 
heated  will  cause  the  first  side  welded  to  crack  unless  the 
operator  is  extremely  cautious.     Therefore  it  is  always  well 
to  learn  how  to  penetrate  the  entire  thickness  of  the  metal 
from  one  side  and  make  a  satisfactory  weld  in  this  manner. 

(125)  As    previously    stated,    aluminum    when    melted 
loses  most  of  its  strength,   and  if  not  supported  by  some 
means  or  other  the  metal  will  collapse.     On  account  of  this 
it  is  advisable  to  back  up  aluminum  work,  when  possible, 
whether  the  job  is  to  be  done  cold  or  in  preheated  condition. 
The  most  successful  manner  of  backing  up  is  shown  in  Fig. 


ALUMINUM  WELDING 


115 


78,  wherein  A  represents  a  thin  sheet  of  copper  which  has 
been  fitted  to  the  work,  and  daubs  of  asbestos  cement  shown 
at  B  will  aid  to  some  extent  in  holding  the  plate  in  position, 
but  this  alone  should  not  be  depended  upon.  A  prop  or 
fire  brick,  upon  the  top  of  which  has  been  placed  a  cushion 
of  cement,  will  serve  as  a  good  backing,  but  where  this  cannot 
be  accomplished  filler-rods  may  be  bent  in  the  manner  shown 
in  Fig.  78.  These  filler-rods  are  not  of  the  springy  type, 
but  are  of  soft  wire  and  the  loop  as  shown  is  not  for  a  spring 


FIG.  78.— One  Method  Used  to  "  Back  Up  "  Aluminum  Work,  when  Welding. 
A  Represents  a  Sheet  of  Copper;  B,  Asbestos  Cement. 

effect,  but  merely  to  take  care  of  the  contraction  and  expan- 
sion of  the  wire.  Copper  is  given  a  preference  over  most  of 
the  other  sheet  metals,  because  it  can  be  peened  with  a  hammer 
to  any  shape  desired,  and  many  odd  shaped  additions  can 
be  formed  by  its  use. 

(126)  The  use  of  clamps,  when  working  on  aluminum,  is 
not  recommended  on  account  of  the  great  conductivity  of 
heat  and  the  weakening  of  the  metal  as  it  approaches  the 
melting-point.  Pressure  of  any  kind  is  not  desired  and  the 


116  OXY-ACETYLENE  WELDING  MANUAL 

operators  who  attempt  to  use  clamps  will  regret  it  sooner  or 
later. 

(127)  In  aluminum  work  contraction  and  expansion  take 
place  the  same  as  in  other  metals,  only  to  a  much  greater 
extent,   and  greater   allowances  must  be  made.     However, 
the  same  rules  can  be  applied  when  determining  whether 
work  should  be  preheated  or  not,  for  if  the  ends  are  free  to 
move,  the  work  can  usually  be    accomplished  without  pre- 
heating,  whereas  if  confined,  it  will  be  necessary.     When 
preheating  is  necessary  the  whole  piece  must  be  treated  in  the 
same  way,  regardless  of  the  size.     If  only  part  of  the  work 
were  preheated  and  the  balance  left  exposed,  it  would  be  almost 
impossible  to  avoid  warpage  and   shrinkage  strains,  which 
would  render  the  work  useless.     Always  preheat  the  entire 
piece  if  any  portion  requires  it. 

(128)  Great  care  must  be  exercised  when  setting  up  alumi- 
num work  for  preheating.     Its  weight  should  be  distributed 
equally  on  whatever  support  is  used,  so  that  there  will  be  no 
danger  of  any  one  part  sagging,  thereby  throwing  the  whole 
piece  out  of  alignment.     A  good  way  of  accomplishing  this 
is  to  lay  fire  bricks  on  their  flat  side,  in  such  a  manner  that  the 
weight  of  the  work  will  be  fairly  well  distributed.     Then  put 
a  daub  of  clay  or  asbestos  cement  on  each  brick  and  press  the 
aluminum  piece  down  on  this  cushion.     This  will  overcome 
the  use  of  shims  and  other  methods  used  for  jacking  up  the 
work,  which  are  unreliable. 

(129)  If  charcoal  is  to  be  used  as  a  preheating  fuel,  an 
oven  of  fire  brick  should  be  built  up  with  draft  holes  in  the 
bottom  layer  of  brick,  as  described  in  the  chapter  on  Pre- 
heating.    A  layer  or  two  of  charcoal  is  then  ignited.     The 
oven  is  then  covered  with  asbestos  paper  or  a  piece  of  sheet 
metal.     Asbestos  paper  is  preferable  as  the  metal  becomes 
very  hot  and  is  apt  to  burn  the   operator.     After  the  fire 
has   received   a   good   start,    additional    charcoal   is   added 


ALUMINUM  WELDING  117 

until  sufficient  heat  is  obtained.  This  can  be  determined  by 
sprinkling  a  little  sawdust  on  the  surface  of  the  aluminum, 
and  if  it  chars  readily,  the  work  is  ready  to  weld,  Other 
methods  have  been  outlined  previously,  any  or  all  of  which 
may  be  used  in  learning  this  heat.  In  executing  the  weld 
as  little  of  the  work  is  exposed  to  the  air  as  possible,  in  order 
to  hold  a  uniform  heat  and  not  permit  any  part  to  become 
chilled.  At  the  completion  of  the  weld  the  oven  is  covered 
over,  the  openings  in  the  bottom  row  of  bricks  are  stopped 
up,  and  the  piece  allowed  to  cool  with  the  dying  fire.  The 
charcoal  process  is  the  slow  but  sure  method  of  handling 
preheated  aluminum  work,  and  is  always  recommended. 

(130)  When  preheating  aluminum  with  torches  burning 
kerosene  or  gas  a  different  kind  of  oven  is  built,  as  previously 
described  in  the  lecture  on  Preheating.  No  openings  are  left 
in  the  lower  row  of  bricks  and  the  oven  is  built  very  much 
closer  to  the  work  being  preheated.  As  the  object  is  to  con- 
fine as  much  heat  as  possible  and  have  a  uniform  tempera- 
ture throughout,  it  is  not  desirable  to  have  such  ovens  loosely 
constructed.  If  the  bricks  are  irregular,  a  double  wall  can 
be  built  with  a  layer  of  asbestos  between  them.  Such  a  pro- 
cedure is  always  recommended  if  time  and  bricks  permit. 
A  hole  is  left  in  one  end  of  the  oven  for  the  preheating  torch 
flame  to  enter.  On  aluminum  work  the  flame  is  never  played 
directly  upon  the  metal.  A  baffling  plate  of  metal  or  fire 
brick  is  used  to  distribute  the  flame  around  the  sides  of  the 
piece  and  very  satisfactory  results  may  be  obtained  by 
preheating  in  this  manner. 


118  OXY-ACETYLENE  WELDING  MANUAL 

PART  THREE.— ALUMINUM  WELDING 

(131)  MANY  times  aluminum  crank  cases  which  have  large 
holes  punched  in  them  and  parts  missing  are   brought  to  a 
welder  for  repairs.     A  question  arises  as  to  whether  it  is  best 
to  back  up  these  holes  and  fill  in  the  missing  parts  with  a 
filler-rod  as  the  welding  progresses,  or  whether   these  parts 
should  be  cast  separately  or  cut  out  of  another  crank  case. 
It  will  generally  depend  upon  the  size  of  the  hole,  as  to  the 
desirable  procedure  in  a  case  of  this  kind.     It  must  be  re- 
membered that  if  the  casting  and  welding  are  to  be  done  at 
one    and    the    same    time   each   additional    layer   of   metal 
must  be  fused  to  the  last  layer  and  that  in  reality  a  great  deal 
of  welding  is  necessary.     In  addition  this  added  metal  must 
be  fused  to  the  crank  case.     On  small  holes,  perhaps  two  or 
three  inches  in  diameter,  this  method  is  recommended,  but 
if  the  hole  is  much  larger,  it  is  best  to  cast  a  piece  and  then 
weld  it  in,  for  in  this  instance  there  is  only  one  line  of  weld 
to  look  after. 

(132)  On  aluminum  work  it  is  proper  to  weld  from  the 
closed  end  of  a  crack  toward  the  open,  whether  the  piece  has 
or  has  not  been    preheated.     This  is  true  also  of  all  other 
metals,  for  if  the  weld  were  to  be  started  at  the  open  end  and 
worked  backwards  there  would  certainly  be  internal  strains 
set  up,  which  would  be  undesirable.     If  it  is  not  clear  which 
end  is  the  open  one,  the  operator  should  stop  a  moment  and 
figure  it  out. 

(133)  Were   a   suspension   arm   of    the   U    type    on    an 
aluminum  crank  case  to  break  about  three  or  four  inches  from 
the  body  of  the  case,  it  could  be  welded  in  place  without  dis- 
mantling the  motor,  if  handled  properly.     Free  access  must 
be  had  to  the  line  of  break,  so  that  the  operator  can  manipu- 
late his  flame  at  whatever  angle  he  thinks  best.     Due  to  the 
contraction  and  expansion,  which  may  throw  the  piece  being 


ALUMINUM  WELDING  119 

welded  out  of  alignment  slightly,  it  is  best  to  blank  the 
bolt  hole  at  the  end  of  this  suspension  arm  and  face  it  off, 
before  the  piece  is  welded  in  position.  Later  a  new  hole  can 
be  drilled  which  will  line  up  accurately  with  the  frame,  and 
the  welder  will  not  then  have  to  worry  or  attempt  to  return 
it  exactly  to  its  former  position.  In  order  to  keep  the  case 
itself  as  cool  as  possible,  wet  asbestos  should  be  packed 
around  it,  near  the  broken  arm,  so  that  too  much  heat  will 
not  be  absorbed  by  it.  The  broken  end  is  then  tacked  in 
position  at  two  or  three  places  and  the  weld  started.  On 
such  a  problem  the  puddle  system  will  be  found  best,  for  both 
horizontal  and  vertical  welding  are  to  be  done,  as  well  as  some 
overhead.  As  flux  causes  the  metal  to  flow,  it  is  rather 
difficult  for  the  beginner  to  apply  it  to  vertical  and  over- 
head work.  The  puddle  stick  should  work  through  the  metal 
its  full  thickness  and  eliminate  every  possible  trace  of  the 
break,  digging  out  the  old  metal  where  dirt  is  found,  and  adding 
new  metal  for  reinforcing.  When  one  side  has  been  welded 
and  reinforced  it  should  not  be  allowed  to  cool  while  the  other 
side  is  being  worked.  The  torch  should  be  played  upon  it 
every  now  and  then,  in  order  that  the  whole  line  of  weld  will 
be  at  approximately  the  same  temperature;  otherwise,  the 
weld  may  break  in  cooling.  The  ease  with  which  aluminum 
is  puddled  together,  which  many  welders  have  likened  to  the 
children's  method  of  making  mud  pies,  seems  so  simple  to  the 
beginner  that  he  cannot  see  where  the  strength  comes  from 
when  cooled.  On  account  of  this,  he  invariably  works  his 
aluminum  too  long.  After  welding  a  few  test  .bars  of  this 
metal  and  breaking  them  in  the  line  of  weld,  many  old  welders 
will  gain  confidence  upon  seeing  the  results  of  their  own 
efforts. 


CHAPTER  X 
WELDING  OF  MALLEABLE  IRON 

(134)  THE  welding  of  malleable  iron,  so  far  as  the  actual 
fusion  of  the  metal  is  concerned,  is  not  practiced  except  in 
very  few  instances,  where  the  parts  are  very  thin  and  have 
been  completely  annealed.  This  is  on  account  of  its  being 
what  might  be  termed  a  heat-treated  metal.  To  begin  with, 
malleable  iron  is  cast  iron,  and  becomes  malleable  only  after 


FIG.  79. — Illustrating  Cross-section  of  Malleable  Iron. 

it  has  been  heated  to  the  proper  condition  in  the  presence  of 
material  which  will  absorb  much  of  its  carbon  content,  and 
kept  in  this  state  until  a  suitable  depth  of  its  exterior  has 
been  annealed.  It  has  been  changed  from  a  brittle  casting 
to  one  which  will  bend  to  some  extent  without  breaking,  and 
its  surface,  by  the  withdrawal  of  the  carbon,  has  been  con- 
verted into  steel.  The  interior  remains  cast  iron.  The 
depth  of  penetration  will  depend  entirely  upon  the  number 

120 


WELDING  OF  MALLEABLE  IRON  121 

of  hours  the  work  is  treated.  Usually  it  runs  from  one- 
sixty-fourth  to  one-eighth  of  an  inch,  depending  upon  the 
type  of  work.  An  idea  may  be  gained  of  how  a  cross-section 
of  this  metal  will  appear,  by  noting  Fig.  79. 

(135)  A  machinist  would  not  think  of  destroying  the  tem- 
per in  his  tools  and  then  attempting  to  use  them  without 
retempering  them.     So  the  welder  will  not  attempt  to  melt 
malleable  iron,  for  he  realizes  that  if  he  were  to  attempt  fus- 
ing this  metal  that  its  character  would  be  entirely  destroyed. 
If  he  should  make  a  fusion,  the  weld  itself  and  in  the  vicinity 
thereof  the  metal  would  be  very  brittle  and  retain  none  of 
its  ductile  qualities.     When- a  weld  of  this  kind  is  attempted, 
first,  a  few  steel  sparks  are  given  off  from  the  surface  of  the 
metal,  which  quickly  diminish  and  the  surface  seems  to  recede 
from  the  flame.     A  white  foam  appears  as  the  steel  surface 
is  burned  and  many  small  blow  holes  then  make  their  appear- 
ance.    The   casting   resembles   a   steel    casting   which    con- 
tains much  sand  and  impurities.     The  welding  of  malleable 
iron,  in  its  broadest  sense,  is  therefore  not  recommended, 
although  as  it  has  been  stated  there  are  occasions  when  it 
can  be  successfully  accomplished.     The  best  manner  of  bond- 
ing malleable  iron  is  by  the  use  of  a  bronze  filler-rod,  and 
this  process  will   hereafter  be  referred  to,   for  convenience, 
as   welding,    although   it   may   resemble    brazing    in    some 
respects. 

(136)  The  art  of  welding  malleable  iron  with  bronze  is 
not  very  difficult  to  learn.     Possibly,  the  greatest  trouble  will 
be  experienced  by  the  beginner  in  distinguishing  malleable 
iron  from  other  castings.     By  again   referring  to  Fig.  43  and 
carefully  noting  the  various  methods  outlined,  this  trouble 
should  be  overcome.     Many  times,  too,  if  the  welder  has 
had  any  mechanical  experience,  he  can  probably  determine 
where  the  casting  has  been  used  and  can  ofttimes  satisfy 
himself  whether  it  is  malleable  or  not.     Malleable  castings 


122  OXY-ACETYLENE  WELDING  MANUAL 

are  very  seldom  used  as  a  wearing  surface,  and  are  generally 
employed  where  there  is  strain,  to  replace  steel  castings  and 
forgings,  which  are  much  more  expensive.  If  it  has  been 
determined  that  the  metal  is  malleable  iron,  half  the  battle 
has  been  won. 

(137)  In  preparing  malleable  iron,  a  clean  surface  is 
necessary  in  the  vicinity  of  the  weld.  No  "  V-ing  "  out  is 
necessary  unless  the  piece  is  greater  than  one-quarter  inch 
in  thickness,  and  then  the  surface  of  the  "  V  "  should  be  as 
rough  as  possible.  The  ends  are  placed  as  close  together  as 
possible,  the  same  as  in  brazing,  and  a  welding  tip  which  is 
one  size  smaller  than  would  be  used  on  the  same  thickness 
of  cast  iron  is  then  used,  with  a  slightly  carbonizing  flame. 
See  Fig.  23.  The  work  is  heated,  the  same  as  in  cast  iron 
and  steel.  This  flame  is  played  directly  on  the  work  in  a 
vertical  position,  similar  to  that  used  in  preheating  the  weld 
in  cast  iron  and  steel,  until  heated  to  a  cherry  red,  back  about 
one-half  inch  on  each  side  of  the  weld.  As  soon  as  this  heat 
is  obtained,  the  bronze  filler-rod  carries  a  quantity  of  bronze 
flux  to  the  weld  and  this  further  tends  to  clean  the  surface. 
With  the  end  of  the  filler-rod  directly  in  contact  with  the 
work  nearest  the  operator,  the  neutral  flame  melts  the  end 
of  the  rod,  which  immediately  should  run  over  the  adjoining 
surface  and  through  the  crack.  When  this  occurs  the  flame 
is  abruptly  twisted  away  from  that  portion  of  the  weld  to 
avoid  burning  the  bronze.  This  is  repeated  along  the  line 
of  the  weld  until  the  entire  surface  is  covered  with  a  thin 
coating  of  bronze.  With  this  as  a  foundation  more  bronze 
is  added,  but  during  this  process  the  torch  is  turned  so  that 
the  neutral  flame  will  not  bear  down  directly  on  the  bronze, 
which  has  already  been  added.  It  should  rather  strike  it  at 
an  angle  and  radiate  enough  heat  from  the  side  of  the  neutral 
flame  to  permit  a  fusion  between  the  filler-rod  and  the  bronze 
already  added.  Much  more  surface  should  be  covered  and 


WELDING  OF  MALLEABLE  IRON  123 

more  of  a  reinforcement  made  than  in  either  cast  iron  or 
steel,  in  order  to  warrant  enough  strength  for  this  class  of 
work. 

(138)  A  good  bronze  for  welding  purposes  should  work 
easily  under  the  influence  of  the  oxy-acetylene  flame  and 
have  sufficient  alloys  present  to  take  care  of  those  destroyed 
by  the  action  of  the  flame.     It  is  not  thought  advisable  to 
work  over  welds  of  bronze,  for  fear  of  making  them  porous, 
unless  more  filler-rod  is  added  whenever  the  flame  is  brought 
in  contact  with  the  weld. 

(139)  Welds  of  malleable  iron  can  be  made  which  will 
be  even  stronger  than  the  surrounding  metal,  and  at  times 
they  can  be  reinforced  by  adding  small  strips  of  steel.     These 
can  be  entirely  covered,  to  make  them  inconspicuous.     Con- 
trary to  custom  it  is  recommended  that  plenty  of  flux  be  used, 
for  best  results  have  been  found  when  a  surplus  rather  than 
a  sparing  amount  has  been  employed. 

(140)  The  matter  of  heat  in  malleable  iron  is  of  con- 
siderable importance.     If  not  enough  heat  is  used  there  will 
be  no  fusion  between  the  bronze  and  the  iron,  whereas  on 
the  other  hand,  if  too  much  heat  is  used,  the  bronze  will  not 
adhere,  but  will  seem  to  boil  on  the  surface  and  form  in  small 
globules  rather  than  spread  over  the  whole  metal.     In  addi- 
tion the  character  of  the  piece  being  worked  on  will  be  changed 
when  heated  too  much.     This  matter  of  heat  should  be  given 
great  attention  and  the  beginner  should  learn  and  have  em- 
phasized the  fact  that  the  proper  heat  is  one  which  will  per- 
mit the  bronze  to  run  like  water  over  the  surface,  and  this 
will  form  a  good  foundation  to  work  upon. 

(141)  In  general,  malleable  iron  work  is  seldom  preheated, 
for  this  is  not  necessary  if  the  pieces  have  been  fitted  together 
as  closely  as  possible  before  the  weld  is  started.      Once  the 
student  has  learned  the  flow  of  metal  and  how  to  reinforce 
his  weld,  he  will  be  in  a  position  to  handle  most  any  kind  of 


124  OXY-ACETYLENE  WELDING  MANUAL 

malleable  iron  properly.  It  is  well  to  remember,  however, 
that  malleable  iron  is  allowed  to  cool  slowly  and  is  not 
immersed  in  water,  as  has  been  suggested  when  working  on 
brass,  for  here  we  have  one  metal  in  the  piece  itself  and 
another  in  the  weld,  and  too  great  a  strain  would  set  up  if 
they  were  cooled  abruptly. 


CHAPTER  XI 
OXY-ACETYLENE  CUTTING 

(142)  BY  heating  a  bar  of  wrought  iron  or  steel  to  a 
welding  heat  and  holding  it  in  a  stream  of  compressed  air, 
or  a  strong  blast,  it  will  at  once  begin  to  melt  and  sizzle, 
emitting  an  incandescent  and  scintillating  light.     This  light 
is  dangerous  to  observe  at  close  range  without  colored  glasses. 
The  burning  of  the  metal  can  be  maintained  for  hours,  without 
any  other  source  of  heat  except  that  caused  by  the  combus- 
tion of  the  iron.     The  oxy-acetylene  cutting  process  is  based 
upon  this  principle,  in  that  a  neutral  flame  is  applied  in  order 
to  heat  the  part  being  cut  to  the  desired  temperature.     Once 
the  melting-point  is  reached,  pure  oxygen  under  pressure  is 
applied   to   maintain   oxidation   and  force  out  the   burned 
portion. 

(143)  The  apparatus  used  for   cutting  does  not  differ 
to  any  great  extent  from  that  of  the  welding  class,  except  that 
a    different    torch    is    employed.     There    are    combination 
regulators  and  torches  manufactured,  but  a  combination  tool 
is  always  regarded  by  most  authorities  as  a  loss  in  efficiency, 
either  on  one  side  or  another.     While  a  low-pressure  welding 
regulator  may  be  used  on  the  oxygen  line  for  cutting,  yet  its 
use  upon  large  work,  where  the  pressure  is  high  and  the  regu- 
lator must  pass  a  great  deal  of  gas  very  freely  without  freezing 
up,  this  low-pressure  regulator  will  be  a  serious  handicap  and 
cause  much  trouble,  if  used. 

(144)  An  ideal  arrangement  on  the  oxygen  line  for  cutting 
is  to  have  a  double  or  "  twin  "  regulator  attached  to  the  oxygen 

125 


126 


OXY-ACETYLENE  WELDING  MANUAL 


drum,  one  side  of  which  will  do  for  welding  and  the  other, 
being  high-pressure  type,  will  produce  a  constant  flow  of 
high-pressure  gas,  suitable  for  the  cutting  jet.  Then  when 
cutting  is  done  a  three-hose  torch  should  be  employed.  One 
of  its  oxygen  connections  which  governs  the  neutral  flame 
can  be  connected  to  the  low-pressure  regulator,  while  the 


FIG.  80. — The  Cutting  Torch  Eats  its  Way  through  Steel  of  any  Size  with 
Remarkable  Ease,  Leaving  a  Clean-cut  Edge.  This  View  Shows  a  Cutting 
Torch  in  Operation  at  the  Ordnance  Welding  School,  U.  S.  Army. 

oxygen  jet  should  be  controlled  by  the  high-pressure  regulator, 
the  third  connection  will  furnish  the  acetylene  gas  for  the 
preheating  flame.  However,  in  place  of  this  three-hose 
arrangement,  most  cutting  is  accomplished  by  means  of  a 
two-hose  apparatus,  wherein  only  one  hose  is  used  to  convey 
the  oxygen  from  a  single  regulator  to  the  torch.  On  such 


OXY-ACETYLENE  CUTTING  127 

apparatus  much  trouble  is  usually  experienced  in  cutting 
old  metals  where  a  great  deal  of  scale  is  present  or  in  a  close 
place  where  the  torch  is  apt  to  get  hot. 

(145)  Many  times  part  of  the  scale  or  metal  will  pop 
up  against  the  tip  and  cause  the  oxygen  jet  to  flicker.     This 
slight  variation  may  cause  an  excessive  pressure  of  oxygen 
to  be   introduced   into   the  preheating  flame  momentarily, 
by  backing   up   the   oxygen  in   the   cutting  jet.     This   lean 
mixture  of  gas  will  generally  flash  back  instantaneously  and 
will  deposit  a  layer  of  carbon  on  the  inside  of  the  tip,  which 
causes  much  annoyance  to  the  operator.     This  condition  is 
to  be  found  where  there  is  but  one  oxygen  line.     In  the  two- 
hose    arrangement    this    is   entirely   overcome,   due   to   the 
independence  of  the  pressure  on  each  line. 

(146)  The  high-pressure  regulator  differs  from  the  low- 
pressure  regulator   in    these  respects:    The  diaphragm,  see 
Fig.  1 6,  is  much   smaller  in  diameter,  which  makes  it  less 
sensitive,    and   of   course   much   stronger.     The   diaphragm 
springs  are  usually  much   heavier;    the  nozzle  contains  a 
larger  opening  for  passing  gas  freely  without  freezing;   and 
to  take  care  of  the  increased  pressure  on  the  line,  usually  a 
higher  pressure  working  gauge  is  added  to   the  regulator. 
Such  a  regulator  is  capable  of  passing  much  more  gas  than 
the  low-pressure  type,  but  as  far  as  being  as  sensitive  and 
maintaining  a  constant,  absolute  flow  of  gas,  its  design  will 
not  permit  it  to  do  so.     In  cutting,  these  requisites  are  not 
necessary.     In  welding,  however,  the  delicate  adjustment  of 
the  flame  demands  a  very  sensitive  regulator  and    usually 
the  larger  the  diameter  of  the  diaphragm  the  more   sensi- 
tive the  adjustment. 

(147)  The  cutting  torch  differs  from  the  welding  torch 
in  many  respects.    The  tip  itself,  when  looking  at  its  end, 
may  resemble  any  one  of  the  views  shown  in  Fig.  81.     In 
the  welding  torch,  but  one  hole  is  to  be  found  in  the  tip; 


128  OXY-ACETYLENE  WELDING  MANUAL 

in  the  cutting  tips,  two  or  more  holes  are  to  be  found.  In 
all  cases  the  center  hole  passes  pure  oxygen,  whereas  in  the 
surrounding  holes,  both  oxygen  and  acetylene  mix  and  when 
lighted  give  a  neutral  flame.  This  will  hereafter  be  called 
the  preheating  flame.  The  gases  issuing  from  these  openings 
are  controlled  by  three  valves,  one  of  which  may  have  a 
trigger  or  lever  arrangement  for  quick  action,  and  it  will 
control  the  center  jet  of  oxygen  which  really  does  the  cutting. 
This  is  under  much  higher  pressure  than  the  preheating 
flame.  The  other  two  valves  will  control  the  oxygen  and 


FIG.  81. — End  Views  of  Cutting  Tips,  Showing  Possible  Arrangements  of 
Preheating  Flames  in  Regard  to  Oxygen  Jet.  The  Black  Circles  Repre- 
sent the  Preheating  Flames,  which  Vary  in  Number  and  Arrangement 
According  to  the  Nature  of  the  Work,  the  Possible  Limit  being  a  Con- 
tinuous Circle,  as  Shown.  The  White  Circles  Illustrates  the  Oxygen 
Jet,  which,  too,  Varies  in  Size  According  to  the  Work. 

acetylene  gases  used  for  the  preheating  flame.  In  lighting 
such  a  torch,  the  acetylene  is  turned  on  in  the  same  manner 
as  has  been  taught  when  welding,  until  it  just  leaves  the  end  of 
the  tip.  Then  the  oxygen  valve  is  opened,  which  controls 
the  preheating  flame,  and  enough  is  permitted  to  pass  to 
produce  a  neutral  flame.  As  soon  as  this  has  been  accom- 
plished, the  third  valve  should  be  quickly  opened  and  held 
so  a  moment,  to  see  if  the  neutral  flame  has  been  changed. 
Generally  this  operation  will  deprive  the  neutral  flame  of 
some  of  its  oxygen,  and  a  feather  flame,  showing  too  much 


OXY-ACETYLENE  CUTTING 


129 


acetylene  and  not  enough  oxygen  gas,  can  be  noticed.  This 
will  necessitate  turning  on  slightly  more  oxygen  at  the  torch 
valve.  The  third  valve  is  then  shut  off  and  the  torch  is  ready 
to  start  cutting. 

(148)  On  small  cutting  jobs,  about  as  much  acetylene 


(Courtesy  of  the  General  Welding  &  Equipment  Co.) 

FIG.  82.— Cutting  a  Heavy  Shaft. 

pressure  is  used  on  the  line  as  there  would  be  if  it  were  a 
welding  job.  The  oxygen  pressure,  however,  is  generally 
much  greater,  and  a  pressure  anywhere  from  ten  to  two 


130  OXY-ACETYLENE  WELDING  MANUAL 

hundred  pounds  should  be  used,  depending  upon  the  thick- 
ness of  the  metal  and  the  conditions  which  must  be  met. 
In  extreme  cases  where  very  heavy  cuts  are  to  be  made,  a 
much  higher  pressure  than  has  been  mentioned  should  be 
used,  but  the  limitations  given  will  cover  a  wide  range  of 
work.  To  start  a  cut  it  is  necessary  to  bring  the  preheating 
flame  in  contact  with  one  edge  of  the  metal  to  be  cut  and  play 
it  there  until  the  metal  is  red  hot.  As  soon  as  this  condition 
is  reached  the  torch  is  held  steady — the  neutral  flame 
just  touching  the  metal;  then  the  third  valve  controlling 
the  cutting  jet  of  oxygen  is  opened.  This  oxygen,  under  high 


FIG.  83. — Position  to  Hold  Torch  in  when  Cutting  Metal. 

pressure,  quickly  acts  upon  the  hot  metal  and  severs  it  instan- 
taneously, melting  and  oxidizing  the  metal  so  that  it  will  not 
flow  together,  in  one  and  the  same  operation.  As  soon  as 
this  occurs  the  torch  should  be  advanced  as  rapidly  as  possible 
in  the  direction  the  metal  is  to  be  cut.  The  more  rapid  the 
advancement  and  the  steadier  the  torch  is  held  the  cleaner 
the  cut  will  be;  and  incidentally,  less  gas  consumed  in  the 
execution  of  the  job.  In  cutting,  as  in  welding,  it  is  always 
well  to  give  the  torch  a  chance,  and  when  the  operator  sees 
much  molten  metal  splashing  directly  back  on  the  torch,  he 
should  change  the  angle  slightly  to  avoid  his  apparatus 
becoming  overheated.  It  has  been  found  that  if  the  cutting 


OXY-ACETYLENE  CUTTING  131 

torch  is  held  at  the  angle  shown  in  Fig.  83,  the  most  satisfac- 
tory results  can  be  expected. 

(149)  At  the  present  time  only  such  metals  as  steel  and 
wrought  iron  can  be  successfully  cut.  When  it  comes  to 
cast  iron  no  method  has  yet  been  discovered  to  cut  it  with 
any  degree  of  success  by  the  oxy-acetylene  flame,  on  account 
of  the  high  melting-point  of  the  oxide  and  various  other  mat- 
ters. The  day  is  looked  forward  to,  however,  when  after 
sufficient  time  and  study  has  been  devoted  to  this  subject, 


FIG.  84.— Method  of  Cutting  with  Two  Welding  Torches.  Torch  A  is  Adjusted 
so  that  a  Neutral  Flame  will  do  the  Preheating,  while  a  Fork  in  the  Oxygen 
Line  Supplies  Oxygen  only  to  Torch  B,  and  it  does  the  Cutting. 

that  cast  iron  can  be  as  successfully  cut  as  any  other  metal, 
by  introducing  another  gas  or  agent  to  destroy  some  of 
the  reactions  which  retard  its  application  at  the  present 
time. 

(150)  The  use  of  the  cutting  torch  in  preparing  steel 
work,  for  welding  of  large  size,  plays  an  important  part,  in 
quickly  and  efficiently  "  V-ing"  out  and  getting  it  ready  for 
use.  Care  should  be  taken,  after  its  use,  to  see  that  the 
heavy  oxide  which  it  leaves  is  largely  destroyed,  before  any 
more  metal  is  added. 


132  OXY-ACETYLENE  WELDING  MANUAL 

(151)  Frequently  the  welder  has  a  call  for  a  cutting 
torch,  where  none  is  available,  yet  an  extra  welding  torch 
or  two  may  be  on  hand.  If  this  is  the  case,  two  welding 
torches  may  be  fastened  together  in  such  a  manner  that  a 
temporary  job  of  cutting  may  be  handled.  The  arrange- 
ment shown  in  Fig.  84  illustrates  this  point.  If  no  extra 
welding  torch  is  available,  a  carbon  burning  torch  or  any  piece 
of  copper  tubing  which  has  a  valve  in  one  end,  suitable  for 
taking  a  hose  connection,  and  the  other  end  free  to  have  a 
welding  tip  brazed  on,  can  be  used  in  the  same  manner.  The 
welding  torch  will  give  the  neutral  flame  and  the  extra  line 
of  oxygen  will  do  the  cutting.  It  is  well  to  remember  that 


FIG.  85. — When  no  Edge  is  Available  to  Start  the  Cut  on  Large  Work,  Much 
Time  may  be  Saved  by  Making  a  Curl  with  a  Cold  Chisel,  as  Shown. 

oxygen,  no  matter  under  what  pressure,  cannot  be  expected 
to  act  upon  cold  metal.  A  red  heat  is  absolutely  necessary. 
There  are  various  short  cuts,  it  is  true,  in  obtaining  this  heat, 
and  where  a  large  shaft  is  to  be  cut,  the  operator  would  not 
think  of  playing  his  torch  upon  such  a  piece  of  metal  until 
it  was  red  hot  in  the  locality  in  which  he  wished  to  start 
his  cut.  This  would  consume  too  much  time  and  gas.  Gen- 
erally a  hammer  and  cold  chisel  are  brought  into  play  and  a 
slight  curl  on  the  metal  is  obtained  as  shown  in  Fig.  85. 
The  moment  this  becomes  red  hot,  the  oxygen  jet  may  be 
turned  on,  and  the  cut  commenced.  As  soon  as  started,  the 
operator  is  able  to  "  carry-on  "  at  will, 


OXY-ACETYLENE  CUTTING  133 

(152)  An  armored  hose  is  generally  used  on  the  oxygen 
line  for  cutting,  as  well  as  on  the  acetylene  line,  as    there  is 
much  more  pressure  used  in  cutting  than  in  welding.     This 
type  of  hose  wears  much  longer  and  does  not  kink  to  the  extent 
that  the  unprotected  hose  does.     The  armor  protects  both 
lines  from  being  burned  by  the  melted  metal,  which  is  very 
apt  to  come  in  contact  with  the  rubber,  were  it  not  protected' 
in  some  manner. 

(153)  The   question   often   arises   in   welding   circles,   as 
to  why,  since  the  cutting  torch  contains  a  series  of  neutral 
flames,  it  would  not  be  just  as  well  to  use  such  a  method  in 
welding,  as  no  doubt  more  heat  could  be  obtained  and  a  greater 
surface  handled.     The  answer  to  such  a  question  would  be, 
that  the  opportunity  for  oxidation  is  so  great  that  successful 
welding  could  not  be  expected,  although  if  this  were  the  last 
means  at  a  welder's  disposal,  he  would  certainly  be  justified 
in  making  a  weld  in  this  manner.     He  should  be  very  careful, 
however,  to  see  that  his  extra  oxygen  supply  is  completely 
shut  off  and  that  there  is  no  possible  chance  for  that  gas 
leaking  into  the  weld. 

(154)  To  plunge  a  flame,  such  as  is  used  in  the  cutting 
torch,  under  water  and  see  it  continue  to  burn  while  sub- 
merged, looks  quite  marvelous  to  the  average  layman.    Yet  in 
cutting  piling  along  water  fronts  this  is  continually  being  done. 
Not  only  does  the   torch   stay  lighted,  but  it  retains  much 
of  its  efficiency  as  a  cutting  tool,  and  some  instances  have  been 
recorded  where  cutting  has  been  accomplished  at  a  depth  of 
thirty  feet  under  the  sea.     It  is  true  that  the  water  conducts 
a  large  part  of  the  heat  away  very  rapidly,  but  to  facilitate 
such  operations,  an  air  line  is    brought  down  which  ejects 
air  under  the  torch  and  clears  the  water  away  to  some  extent, 
but  this  is  not  necessary.    In  order  to  explain  this  phenomenon 
in  a  very  simple  way,  it  will  be  stated  that  nothing  will  burn 
unless  oxygen  is  present,  and  the  more  oxygen  used,  up  to  a 


134  OXY-ACETYLENE  WELDING  MANUAL 

certain  point,  the  more  rapidly  will  the  burning  take  place. 
When  submerging  the  cutting  torch,  it  is  presumed  that  the 
flame  obtains  what  added  oxygen  is  necessary  from  the  cut- 
ting jet  and  this  together  with  the  velocity  of  the  flame  and 
its  hydrogen  enveloping  flame  permits  the  neutral  flame 
to  continue  burning. 


CHAPTER  XII 
CARBON  BURNING 

(155)  THOSE  who  are  familiar  with  gasoline  engines  will 
know  that  after  being  used  for  some  time,  the  impurities  in 


FIG.  86. — Removing  Carbon  from  U.  S.  Army  Truck,  by  the  Oxygen  Process, 
at  the  Ordnance  Welding  School. 

the  lubrication  oil  and  in  the  gasoline,  which  is  continually 
being  burned,  will  form  around  the  top  of  the  piston  and 
cylinder  head  in  the  motor.  When  enough  has  been  deposited 

135 


136  OXY-ACETYLENE  WELDING  MANUAL 

and  a  few  high  points  become  overheated  through  long  run- 
ning, there  will  be  a  metallic  knock  distinctly  heard  when  an 
extra  strain  is  being  exerted  by  the  motor.  This  layer 
of  impurities  is  called  carbon  and  its  presence  means  loss  of 
power.  Owing  to  the  construction  of  most  cylinder  blocks, 
it  is  a  very  difficult  matter  to  reach  this  portion  of  the  block 
without  dismantling.  This  requires  skilled  labor  and  means 
much  delay.  A  method  of  removing  this  carbon  by  the  oxy- 
gen process  has  been  devised,  which  will  save  much  time  and 
trouble. 

(156)  To   remove   carbon   from   a   gasoline   engine,   first 
shut  off  the  gasoline  in  the  line  and  allow  the  engine  to  run 
until  all  gas  has  been  removed  from  the  carburetor.     This 
is  merely  a  safety  measure.     If  a  vacuum  feed  is  used,  the 
vacuum  tank  is  drained,  as  it  would  require  much  time  for  the 
engine  to  consume  this  amount  of  gas.     The  hood  of  the  car 
is  then  removed  and  all  parts  of  the  motor  on  the  side  where 
the  burning  is  to  be  done  are  covered  with  asbestos  paper 
or  by  a  heavy  piece  of  canvas  which  has  previously  been 
dampened.     This  is  to  keep  the  sparks  from  dropping  into 
the  apron  or  oily  parts  of  the  machine.     Remove  the  spark 
plugs  and  see  from  the  condition  of  these  spark  plugs  whether 
the  cylinder  is  dry  or  oily.     An  oily  cylinder  will  burn  out 
much  more  rapidly  than  when  dry.     This  can  be  detected 
very  easily  from   the  condition  of  the  spark  plugs.     It  is 
recommended  that  only  the  spark  plugs  be  removed  as  the 
removal  of   the  bonnet  or  any  larger  portion  will  require 
much  more   oxygen   and   will   not  produce   as   satisfactory 
results  as  when   the  oxygen  is  introduced  through  a  small 
opening. 

(157)  Place  the  carbon  removing  apparatus,  which  con- 
sists of  the  oxygen  drum,  regulator,  a  length  of  hose  and 
carbon  burning  torch,  the  latter  being  made  up  principally 
of  a  shut-off  valve  and  a  long  length  of  small  copper  tubing 


CARBON  BURNING 


137 


as  shown  at  A  in  Fig.  87 .    Turn  on  not  over  twenty-five  pounds 

oxygen  pressure  as  far  as  the  torch,  and  the  apparatus  is  then 

ready  to  use.     With  the  torch  inserted  through  the  spark 

plug  hole  in  number  one  cylinder,  that  is,  the   one  nearest 

the  radiator,  guide  the  rise  of  the  piston  until  it  is  at  the  top 

of  the  stroke.     This  means  that  both  intake  and  exhaust 

valves  are  closed.     On  automobiles  where  a  self  starter  is 

used,  it  will  be  necessary  to  use  a  crank 

for  turning  over  the  motor.     With  the 

piston  at  the  top  of  the  stroke  and  both 

valves    closed,    there    is    only    a   small 

portion    of    the    cylinder    head    to    be 

worked  upon  and  this  is  the  part  which 

has    the   carbon  deposit  upon  it.     All 

machined  surfaces  and  valve  seats  are 

fully  protected  and  will  not  be  subjected 

to  any  exposure  during  the  burning.     If 

the  cylinder  seems  very  dry,  a  teaspoon 

of  alcohol  or  kerosene  may  be  sprayed 

into  it  through  the  spark  plug  port,  to 

facilitate  the  clearing  of  the  carbon.     If 

the  cylinder  is   somewhat  oily,  this  is 

not    necessary.     A   match    or   burning 

taper  is  then  held  over  the  hole  and  a 

stream  of   oxygen  will  carry  the  flame 

down  into  the  cylinder  and  ignite  the 

carbon.      As    soon    as    this    occurs,    a 

small  cracking  noise  can  be  heard  and  the  carbon  will  run 

around  the  inside  of  the  cylinder  in  a  heated  condition.     The 

part  around  the  valves  should  be  cleaned  of!  first,  before 

going  to  the  inner  chamber,  as  this  process  does  not  seem  to 

work  very  well  if  performed  the  other  way.     A  roaring  noise 

will   be   in  evidence   and   the  popping  of   the   carbon  from 

the   surface  as    it   frees  itself    may  frighten    the    operator 


FIG.  87. — Carbon  Burn- 
ing Apparatus.  The 
Small  Copper  Tube  A 
is  Flexible  and  can  be 
Bent  in  any  Shape 
Desired. 


138  OXY-ACETYLENE  WELDING  MANUAL 

when  attempting  his  first  job,  but   there  is  absolutely  no 
danger. 

(158)  It  must  be  remembered  that  oxygen  itself  does  not 
burn,  but  merely  assists  the  other  inflammable  material  in 
burning,  therefore  it  is  only  the  carbon  which  is  contained 
in  the  cylinder  that  in  this  case  does  the  burning.     As  soon 
as  this  is  all  consumed,  there  will  be  nothing  else  to  burn  and 
the  sparks  will  die  of  their  own  accord.     When  this  occurs, 
the  operator  will  shut  off  his  torch,  blow  the  cylinder  out 
with  compressed  air  and  replace  the  spark  plug  and  then 
proceed  with  the  next  cylinder,  which  he  will  treat  in  the 
same  manner.     He  must  be  sure,  however,  that  the  piston 
in  cylinder  number  two,  or  whatever  cylinder  he  is  working 
on,  is  moved  to  the  top  of  its  stroke  and  that  both  valves  in 
that  particular  cylinder  are  closed  before  he  starts  his  burn- 
ing.    After  all  cylinders  have  been  treated  like  number  one 
and  the  spark  plugs  are  in  position,  the  gasoline  is  turned  on 
(if  the  vacuum  tank  has  been  drained,  it  is  best  to  fill  this), 
and  the  motor  started,  with  the  exhaust  "  cut  off  "  open, 
in  order  that  any  loose  particles  of  carbon  may  be  blown  out. 

(159)  While   this  process  is   in  very   common   use,   and 
seems  to  be  very  simple,  there  are  many  who  go  through 
the  steps  without  obtaining  satisfactory  results.     It  is  con- 
sidered best,  if  possible,  in  attempting  carbon  burning  for  the 
first  time,  to  try  it  on  some  motor  which  is  about  to  be  over- 
hauled, in  order  that  the  results  may  be  studied  so  that  the 
operator  will  not  go  blindly  on,  without  showing  some  im- 
provement.    Many  times  only  the  high  points  are  burned 
out,  which  will  free  the  motor  temporarily  of  some  of  its 
knocks,  but  within  a  week  or  so  they  will  become  evident 
again.     He  who  will  become  proficient  in  learning  carbon 
burning  should  apply  himself  and  study  his  results. 

(160)  There  are  those  who  consider  carbon  burning  in- 
jurious to  the  motor  on  account  of  the  high  temperature  flame 


CARBON  BURNING  139 

which  they  think  is  introduced.  But  it  is  ignorance  as  to 
the  working  principle  of  this  process  that  makes  them  think 
this.  When  it  is  considered  that  a  gasoline  motor  depends 
upon  a  rapid  succession  of  internal  explosions  for  its  power, 
the  folly  of  condemning  a  process  of  this  nature,  where  abso- 
lutely no  actual  flame  is  used,  will  be  seen.  It  is  only  the 
incandescent  particles  of  carbon  flying  about  that  give  any 
heat  at  all.  After  a  cylinder  has  been  burned  or  decarbonized, 
the  hand  can  be  placed  upon  it  immediately,  without  any 
fear  of  being  burned.  Those  motors  equipped  with  aluminum 
pistons  may  be  handled  in  the  same  way  as  those  of  cast 
iron,  and  when  properly  used  this  method  of  decarbonization 
is  very  satisfactory. 

(161)  Many  times  it  is  asked  how  often  carbon  burning 
is  to  be  recommended.     This  will  all  depend  upon  the  type 
of  motor,  its  condition,  and  to  some  extent,  upon  the  lubri- 
cating oil  and  gasoline  used,  as  well  as  the  mileage  of  the  car. 
If  a  machine  is  being  run  continually,  it  may  be  necessary 
to  have  the  carbon  removed  about  every  two  months,  but 
conditions  will  ter  i  to  lengthen  or  shorten  this  time  as  the 
case  may  be.     When  the  knocks  are  in  evidence,  and  the 
loss  of  power  is  noticed,  it  is  time  for  the  carbon  to  be  re- 
moved, and  whether  this  is  one  month  or  two  it  is  an  error 
to   continue  running   the  car  which  is  filled  with  carbon. 
Invariably  the  carbon  burner  is  asked  by  his  customer  whether 
carbon  burning  will  regrind  valves;    this  and  many  other 
questions  can  be  intelligently  answered  and  explained  to  the 
questioner's  satisfaction  if  a  careful  study  of  the  process  is 
made. 

CONCLUSION 

(162)  In  drawing  this  elementary  course  in  oxy-acetylene 
welding  to  a  close,  the  author  wishes  to  again  call  attention 
to  the  fact  that  this  course  is  merely  to  be  considered  as  a 


140 


OXY-ACETYLENE  WELDING  MANUAL 


(Courtesy  of  the  British  Oxygen  Co.) 

FIG.  88.— Photograph  Showing  Square  Piece  Cut  Out  of  a  Steel  Block  9  Inches 

Thick. 


(Courtesy  of  the  Dains-P.ournonmlle  Co.) 

FIG.  89. — This  is  an  Electrically  Driven  Oxy-acetylene  Cutting  Machine 
for  Making  Duplicate  Cuts  on  Steel  from  a  Drawing.  Dies  and  many 
Irregular  Forms  may  be  Produced  at  Low  Cost  by  it. 


CARBON  BURNING 


141 


foundation  upon  which  to  build.  An  effort  has  been  made  to 
confine  the  student's  line  of  thought  exclusively  to  the  actual 
welding  of  the  various  metals  and  an  intimate  knowledge  of 
the  tools  necessary  to  accomplish  this.  Technical  terms  have 
been  avoided  as  much  as  possible,  and  history,  as  well  as  the 


(Courtesy  of  the  Dams-Bournonville  Co.) 

FIG.  90. — This  Shows  a  Motor-driven  Oxy-acetylene  Device  Particularly 
Adapted  to  Cutting  Plates  or  Sheets  into  Round,  Oval,  or  Irregular  Forms 
with  either  Straight  or  Beveled  Edges. 

generation  of  the  various  gases,  have  been  considered  only  of 
secondary  importance  and  have  been  purposely  omitted. 
Many  repetitions  have  been  made  to  place  emphasis  upon 
certain  points  and  methods.  It  is  hoped  that  the  student 
who  pursues  this  course  if  he  has  been  restricted  to  the  use 


142 


OXY-ACETYLENE  WELDING  MANUAL 


of  only  one  apparatus  will  realize  that  there  are  many 
such  on  the  market,  each  one  of  which  may  have  its  advan- 
tages, but  if  the  general  rules,  as  outlined,  are  followed,  he 
will  not  have  much  difficulty  or  be  covered  with  confusion 
if  called  upon  to  operate  different  makes  of  apparatus  for 


FIG.  91. — Quick,  Permanent  Repairs  are  Made  on  Large  Supply  Trucks  in 
the  U.  S.  Army  by  its  Corps  of  Trained  Welders.  This  View  Shows  an 
Individual  Welding  Unit  in  Operation  at  the  U.  S.  Army  (Ordnance) 
Welding  School. 

the  first  time.  If  he  sees  that  there  is  gas  pressure  on  his 
lines,  he  should  not  hesitate,  thereby  showing  his  ignorance 
of  that  particular  type  of  apparatus,  rather  let  him  turn  on 
one  valve,  and  direct  the  stream  of  gas  toward  his  nostrils. 
He  can  then  readily  determine  whether  it  is  the  fuel  gas  or 
not  and  knowing  that  oxygen  will  not  burn  he  can  turn  his 


CARBON  BURNING 


143 


(Courtesy  of  Ben  K.  Smith,  V.  S.  Welding  Co.) 

FIG.  92. — This  Cylinder  did  not  Require  to  be  Bored  or  have  any  other 
Machine  Work  Performed,  but  was  Placed  in  Service  Directly  after 
Welding  and  has  been  Serving  for  over  Three  Years. 


144  OXY-ACETYLENE  WELDING  MANUAL 

fuel  gas  on  and  proceed  without  showing  any  concern.  It 
might  be  said  that  confidence  in  one's  self  is  the  keynote  of 
success,  and  this  is  imperative  to  make  an  expert  welder, 
but  to  the  man  who  studies  the  flame  action  on  his  metals 
and  appreciates  the  apparatus  to  the  fullest  extent,  there  is  a 
very  bright  future. 

(163)  The  welder  who   desires   the  best  results   should 
procure  the  best  apparatus  possible  to  fill  his  requirements. 
The  cost  of  such  is  only  of  secondary  importance,  the  hazard 
attached  to  cheaply  constructed  apparatus  and  the  loss  of 
gas,  time  and  the  execution  of  faulty  work  and  the  depre- 
ciation of  the  welder's  reputation,  are  matters  of  vital  im- 
portance.    The  supplies  too,  such  as  filler-rods  and  the  like, 
should  be  obtained  only  from  reliable  welding  companies 
who  have  their  own  shops  in  which  they  may  test  them.     It 
is  false  economy  indeed,  to  attempt  to  save  a  few  cents  on 
filling  materials,  for  many  dollars'  worth  of  time  and  gas 
may  be  lost  on  account  of  the  failure  of  the  metal  added. 

(164)  There  are  a  few  illustrations  set  forth  herein,  to 
show  what  has  been  accomplished  in  the  way  of  machine 
construction  used  in  adapting  the  oxy-acetylene  process  to 
the  requirements  of  various  manufacturers.     These  will  tend 
to  show  to  some  extent  what  the  future  has  in  store  for  this 
wonderful  process. 

(165)  It    has    been    rightly    stated    that    oxy-acetylene 
welding  is  yet  in  its  infancy.     The  torches,  regulators  and  in 
fact  all  parts  of  the  apparatus  are  constantly  being  improved. 
The  process  of  cutting  cast  iron  must  still  be  solved,  so  it 
will  again  be  stated  that  it  behooves  those  who  are  interested 
in  this  work  to  apply  themselves  to  the  great  future  in  store 
for  them. 


GLOSSARY 


DEFINITIONS  OF  TERMS  AND  WORDS  APPLIED  TO  OXY- 
ACETYLENE  WELDING  AND  CUTTING 

ACETONE.  A  liquid  which  is  capable  of  absorbing  twenty-five  times 
its  volume  of  acetylene  gas  under  normal  temperature  and  pressure. 
Employed  as  a  solvent  in  the  acetylene  cylinder. 

ACETYLENE.    An  inflammable  gas  used  for  welding  and  cutting. 

ACETYLENE  CYLINDER.  A  steel  tank  filled  with  porous  material 
and  acetone,  in  which  acetylene  gas  is  stored. 

ADAPTER.  A  brass  fitting  used  to  connect  regulators  to  different 
cylinders. 

ALIGNMENT.    State  of  being  in  line. 

ALLOY.  Metal  which  is  added  to  another  metal.  A  mixture  of  two 
or  more  entirely  different  metals. 

ANGLE  IRON.  A  steel  bar,  the  cross-section  of  which  forms  an  angle 
of  90  degrees. 

ASBESTOS.  A  fibrous  material  not  affected  by  fire.  Usually  supplied 
in  sheets  or  shredded. 

AUTOGENOUS  WELDING.  The  process  of  uniting  two  pieces  of  metal 
together  by  fusing  without  additional  metal  being  added,  and  without 
the  aid  of  hammering. 

BABBITTED.  Lined  with  Babbitt  metal.  Generally  found  in  bear- 
ings. 

BACK  FIRE.  The  popping  out  of  the  torch  flame,  due  to  a  slight 
explosion  of  the  mixed  gas  between  the  torch  tip  and  the  mixing  chamber. 

BEARING.     Support  or  wearing  surface  for  a  revolving  shaft. 

BEVEL.     To  cut  or  form  at  an  angle. 

BEVELED  EDGE.     An  edge  cut  or  formed  at  an  angle. 

BLOWHOLE.    A  hole  or  cavity  formed  by  trapped  gas  in  metal. 

BLOWPIPE.  A  torch  which  mixes  and  burns  gases  producing  high- 
temperature  flames.  The  term  TORCH  is  given  preference  in  oxy-acety- 
lene  welding  and  cutting. 

145 


146  GLOSSARY 

BRAZING.     Uniting  metals  with  brass  or  bronze  by  means  of  heat. 

BRAZING  WIRE.     A  filler-rod  of  brass  or  bronze  used  in  brazing. 

BUTT  JOINT.     A  joint  made  by  butting  two  edges  together. 

CAP.     A  metal  cover  used  to  protect  cylinder  valves. 

CARBON  BLOCKS.  Carbon  in  block  form.  Used  to  assist  in  building 
up  parts  that  are  to  be  added.  They  may  be  ground  to  any  shape 
desired. 

CARBON  RODS.  Carbon  in  rod  form.  Employed  to  save  holes 
around  which  the  metal  is  melted. 

CARBONIZING  FLAME.     A  flame  with  an  excess  of  acetylene  gas. 

CONTRACTION.     The  shrinkage  of  metal  due  to  cooling. 

CROSS-BAR.  Hand  screw  for  adjusting  the  passage  of  gas  through 
the  regulator. 

CUTTING  JET.  Central  jet  of  oxygen  issuing  from  tip  of  cutting 
torch. 

CUTTING  TORCH.  A  torch  with  one  or  more  heating  jets  and  an 
oxygen  jet,  used  for  cutting  metals  in  the  oxy-acetylene  process. 

CYLINDER.     A  tank  containing  gas  under  pressure. 

DUCTILE.  That  property  which  permits  metal  being  formed  or 
drawn  into  different  shapes  without  breaking. 

EXPANSION.     Increase  in  size  due  to  heating. 

FILLER-ROD.  A  rod  or  wire  used  to  supply  additional  metal  to  the 
weld. 

FILLET  WELD.    A  weld  made  in  a  corner. 

FLAME  PROPAGATION.    The  rate  at  which  a  flame  will  travel. 

FLASH  BACK.  The  burning  back  of  the  gases  to  the  mixing  chamber 
or  possibly  farther. 

FLUX.  Chemical  powder  used  to  dissolve  the  oxides  and  clean 
the  metal  when  welding. 

GAS.  Erroneously  applied  to  acetylene  gas  alone.  Both  oxygen 
and  acetylene  are  in  the  form  of  gas. 

GAUGE.     An  instrument  for  measuring  pressures  of  gases. 

GENERATOR.  A  device  for  manufacturing  gas.  Usually  specified 
as  acetylene  generator  or  oxygen  generator. 

GRAIN.  The  arrangement  of  the  molecules  or  crystals  which  make 
up  a  metal. 

HORIZONTAL  WELDING.    Welding  in  a  level  position. 

I-BEAM.  A  steel  bar  with  the  cross-section  of  an  I.  Sometimes 
called  EYE  BEAM. 

LINE.    Hose  or  pipe  carrying  gas. 


GLOSSARY  147 

MANIFOLD.  A  header  with  outlets  or  branches  by  which  several 
cylinders  of  gas  may  be  used  in  batteries. 

MONEL  METAL.     An  alloy  of  copper  and  nickel. 

NIPPLE.     A  short  piece  of  pipe. 

OVERHEAD  WELDING.    Welding  with  the  torch  overhead. 

OXIDATION.     A  combination  with  oxygen. 

OXIDE.     A  coating  or  scale  formed  by  oxygen  combining  with  metal. 

OXIDIZING  FLAME.    A  flame  with  an  excess  of  oxygen  gas. 

OXYGEN.  A  non-inflammable  gas  used  in  oxy-acetylene  welding 
and  cutting. 

OXYGEN  CYLINDER.  A  steel  tank  for  storing  and  shipping  oxygen. 
Available  for  commercial  work  in  100,  200,  and  250  cubic-foot  sizes. 
The  oxygen  is  compressed  as  free  gas  to  1800  pounds  .pressure  at  68 
degrees  Fahrenheit. 

PEENING.     Stretching  the  surface  of  cold  metal  by  use  of  the  hammer. 

PENETRATION.  A  thorough  welding  completely  through  the  joint 
of  the  pieces  or  parts  being  fused. 

PREHEATING.  The  heating  of  a  metal  part  previous  to  welding. 
Generally  used  to  prevent  strains  or  distortion  from  contraction  and 
expansion;  also  to  save  gas. 

POOL.     A  small  body  of  molten  metal  formed  by  the  torch  flame. 

PUDDLE  STICK.  A  steel  rod  flattened  at  one  end,  used  to  break  up 
oxides,  remove  dirt  and  build  up  additional  metal.  Particularly  help- 
ful in  welding  cast  aluminum. 

PUDDLING.  The  manipulation  of  the  filler-rod  or  the  puddle-stick 
in  such  a  manner  as  to  break  up  oxides,  remove  dirt,  and  aid  in  securing 
a  good  fusion  of  the  metal. 

REDUCING  FLAME.     (See  Carbonizing  Flame.) 

REDUCING  VALVE.     (See  Regulator.) 

REGULATOR.  A  device  for  reducing  and  maintaining  a  uniform 
pressure  of  gas  from  cylinders,  generators  or  shop  lines. 

SCALE.  A  coating  of  oxide  on  fused  iron  or  steel  that  breaks  off  as 
the  metal  cools. 

SCALING  POWDER.     A  name  given  flux. 

SLAG.     The  oxidized  metal  and  scale  blown  out  when  cutting. 

SOLDERING.  Uniting  metals  by  fusing  with  a  different  metal  which 
has  a  much  lower  melting-point  than  the  pieces  to  be  joined.  The  use 
of  a  lead,  tin  and  zinc  alloy  is  called  soft  soldering.  Hard  soldering  is 
similar  to  brazing. 

TACKING.    Fusing  pieces  together  at  one  or  more  places. 


148  GLOSSARY 

TIP.    A  copper  or  brass  nozzle  for  a  welding  or  cutting  torch. 

V.    Angle  or  groove  between  two  beveled  edges  prepared  for  welding. 

V-BLOCK.  Block  cut  out  in  the  shape  of  a  V,  or  angle  iron,  used  in 
lining  up  shafts. 

VALVE.    A  device  for  shutting  off  the  passage  of  gas. 

VERTICAL  WELDING.    Welding  as  applied  to  an  upright  position. 

WELDING  ROD.  Material  used  to  supply  additional  metal  to  the 
weld.  (See  Filler-rod.) 


LECTURES 


NOTE. — In  order  to  determine  whether  the  student  is  obtaining 
the  information  desired  it  is  sometimes  thought  fitting  to  give  written 
examinations.  These  serve  as  an  index  as  to  what  the  student  has 
learned  and  what  he  has  not.  They  also  let  the  instructor  know 
whether  he  is  making  every  point  clear  in  his  training. 

The  following  questions  fit  in  with  each  chapter  or  part  thereof 
and  are  merely  a  suggestion  for  the  instructor  who  has  no  course  of 
training  outlined.  With  one  or  two  exceptions  all  answers  to  these 
questions  may  be  found  within  the  manual.  There  are  a  few  mislead- 
ing questions  purposely  inserted  to  see  if  the  student  is  thinking  for 
himself. 

LECTURE   NUMBER  ONE 

Subject — APPARATUS 

1.  Name  the  different  classes  into  which  oxy -acetylene  welding 
•paratus  may  be  divided  and  explain  the  principles  upon  which  this 

classification  depends. 

2.  Illustrate  by  line  sketches  the  various  locations  of  the  mixing 
chambers  for  the  oxygen  and  acetylene  gases  in  welding  torches. 

3.  (a)  Where  is  the  logical  location  for  the  mixing  chamber  in 
welding  torches  employed  in  automobile  and  tractor  repair  work? 

(6)  Give  reasons  for  so  thinking. 

4.  How  is  the  torch  and  the  welding  tips  treated  after  repeated 
"flash-backs"  have  taken  place? 

5.  Describe  briefly  the  working  principles  of  a  regulator  and  illus- 
trate with  a  simple  sketch. 

6.  Explain  the  difference  between  high  and  low-pressure  regulators. 

7.  (a)  Can    acetylene    regulators    be    interchanged    with    oxygen 
regulators  with  perfect  safety?       Explain  why. 

(6)  How  is  it  possible,  in  majority  of  cases,  to  distinguish  in  a  very 

149 


150  LECTURES 

simple  manner,  between  oxygen  and  acetylene  regulators,  when  no 
gauges  are  attached? 

(c)  Why  does  this  difference  exist? 

8.  (a)  Why  should  all  tension  upon  diaphragm  springs  be  removed 
before  admitting  gas  under  pressure  to  the  regulator? 

(b)  Can  a  regulator  which  has  been  abused  in  this  manner  be 
repaired? 

(c)  What  can  be  employed  as  a  fitting  substitute  for  gallilith? 

9.  Explain  why  the  high-pressure  gauge  on  the  acetylene  regulator 
cannot  be  used  as  an  index  to  the  contents  of  the  attached  cylinder  of 
gas  in  exactly  the  same  manner  as  the  oxygen  high-pressure  gauge. 

10.  Why  is  glycerine  used  as  a  substitute  for  oil  when  regrinding 
torch  valve-seats  with  emery  powder,   and  with  lead-oxide  in  the 
caulking  of  leaky  joints  along  the  line? 

LECTURE  NUMBER  TWO 
Subject — OPERATION 

1.  (a)  Under  what  pressure  is  oxygen  gas  received  in  the  cylinders 
used  commercially? 

(b)  Does  this  pressure  vary  to  any  great  extent  with  changes  in 
temperature? 

2.  (a)  Under  what  pressure  is  acetylene  gas  received  in  the  cylinders 
used  commercially? 

(b}  Does  this  pressure  vary  to  any  great  extent  with  changes  in 
temperature? 

3  (a)  In  setting-up  apparatus  for  the  first  time,  or  in  attaching 
regulators  to  new  cylinders,  what  precaution  should  be  observed 
regarding  cross-bar  on  regulators  before  the  gas  is  turned  on? 

(6)  Where  should  the  operator  stand  when  turning  on  the  gas? 

4.  (a)  How  much  pressure  should  be  placed  on  the  oxygen  hose, 
when  the  torch-valves  are  closed,  before  starting  to  operate  with  a 
medium-sized  tip? 

(b)  How  much  pressure  should  be  placed  on  the  acetylene  hose, 
when  the  torch-valves  are  closed,  before  starting  to  operate  with  a 
medium-sized  tip? 

5.  (a)  After  both  the  oxygen  and  acetylene  gases  are  in  the  line 
hoses  as  far  as  the  torch,  which  valve  on  the  torch  is  opened  first  in  order 
to  light? 

(b}  What  would  happen  if  the  other  torch-valve  were  opened  first? 


LECTURES  151 

(c)  What  would  likely  occur  if  both  valves  were  opened  before  torch 
was  lighted? 

6.  (a)  How  is  it  possible,  when  lighting  torch,  to  determine  whethe 
enough  pressure  is  on  the  acetylene  line  without  looking  at  gauge? 

(b)  How  is  it  possible,  in  the  case  of  oxygen  pressure? 

7.  (a)  What  is  meant  by  a  neutral  flame? 

(b)  How  hot  is  a  neutral  oxy-acetylene  flame? 

(c)  Is  the  temperature  of  a  neutral  flame  the  same  whether  large  or 
small  tip  is  used? 

8.  (a)  If  too  much  acetylene  gas  is  used,    how  will  the  flame  be 
affected? 

(b)  What  action  will  this  have  on  the  weld? 

9.  (a)  If  too  much  oxygen  gas  is  used,  how  will  the  flame  be  affected? 
(b)  What  action  will  this  have  on  the  weld? 

10.  (a)  Explain  briefly  how  apparatus  is  shut-off,  when  not  to  be 
used  for  several  hours  or  more. 

(b)  Why  should  particular  care  be  taken  to  see  that  acetylene  cyl- 
inders are  tightly  closed  when  empty? 

(c)  What  action  does  oxygen  have  on  oils  and  greases? 

LECTURE  NUMBER  THREE 

Subject — WELDING  OF  CAST  IRON 

(Part  One) 

1.  (a)  How  is  it  possible  to  distinguish  cast  iron  from  such  metals 
as  malleable  iron? 

(b)  From  semi-cast  iron? 

(c)  From  cast  steel? 

2.  (a)  What  kind  metal  is  used  in  making  "filler-rod"  used  in  the 
welding  of  cast  iron? 

(b)  What  general  rule  can  be  laid  down  as  to  the  relation  of  the  metal 
in  the  "filler-rod"  to  the  metal  to  be  welded? 

3.  (a)  What  are  the  characteristics  of  good  cast  iron  "filler-rods"? 
(b)  Can  piston  rings  and  other  small  scraps  of  cast  iron   be  used 

successfully  as  "filler-rods"?    Explain  why. 

4.  (a)  What  is  the  purpose  of  a  flux? 

(b)  Is  a  flux  used  in  the  welding  of  cast  iron? 

5.  (a)  Name  one  formula  for  making  a  cast-iron  flux? 

(b)  How  often  is  the  flux  applied,  and  by  what  means? 

(c)  In  what  condition  are  fluxes  kept  when  not  in  use? 


152  LECTURES 

6.  (a)  How  should  the  flame  be  held  in  the  welding  of  all  cast  iron? 
(b)  When  and  how  is  the  "filler-rod"  added  to  the  weld? 

7.  (a)  Name  the  one  principal  cause  of  blow-holes  and  hard  spots 
in  the  weld. 

(b)  Mention  some  of  the  others. 

8.  (a)  When  is  it  advisable  to  grind,  or  "  V  "  out,  the  ends  of  the  pieces 
to  be  welded? 

(b)  When  is  it  not  advisable? 

9.  (a)  Does  the  application  of  heat  cause  contraction  or  expansion  in 
metals? 

(6)  Are  there  any  excepts  to  this  rule?    Name  one. 

10.  (a)  Were  two  cast-iron  bars  measuring  2X12  inches  and  ^-inch 
thick,  to  be  welded,  end  to  end,  what  precaution  should  be  observed  in 
laying  out,  if  the  finished  job  is  to  measure  just  24  inches  long? 

(b}  In  what  respect  would  this  problem  differ  were  the  bars  only  6 
inches  originally  and  the  finished  job  to  measure  12  inches  overall? 

(c)  Is  the  action  of  the  metal  in  the  weld  a  constant,  or  a  variable 
quantity  depending  upon  the  length  of  the  bar  in  this  problem? 


LECTURE  NUMBER  FOUR 

Subject — WELDING  OF  CAST  IRON 
(Part  Two} 

11.  (a)  How  could  a  spoke,  broken  midway  between  the  hub  and  rim, 
of  a  24-inch,  4-spoke  wheel  (otherwise  intact)  be  welded  without  pre- 
heating?    (Use  a  sketch  if  necessary  to  make  method  clear.) 

(b)  If  a  wheel  of  like  size  were  broken  only  in  the  rim,  midway 
between  spokes,  explain  procedure  in  welding  without  preheating. 

(c)  Same  sized  wheel,  broken  only  in  hub; — can  weld  be  made  without 
preheating?     Give  reasons  for  so  thinking. 

(d)  Were  breaks  (a),  (b)  and  (c}  all  present  in  same  wheel,  with  rim 
fracture  on  opposite  side  of  adjoining  spoke  from  break  in  hub,  should 
welding  be  started  at  rim  or  hub?    Why? 

12.  (a)  In  the  building  up  of  broken  or  missing  teeth  in  cast-iron 
gears,  what  procedure  is  necessary  when  no  carbon  blocks  are  available 
for  forms? 

(b)  If  certain  carbon  centers  from  dry  cell  batteries  are  obtainable 
how  should  they  be  treated  before  allowing  molten  metal  to  come  in 
direct  contact  with  them? 


LECTURES  153 

(c)  What  very  important  point  must  be  uppermost  in  mind  when 
dental  work  on  gears  is  being  done? 

(d)  Explain  precautions  taken  in  allowing  work  of  this  nature  to  cool. 
13.  .(a)  Realizing  that  hard  spots  occur  in  most  welds  executed  by 

the  new  welder  and  having  learned  the  cause  of  their  presence  and 
how  to  overcome  them,  would  it  not  be  possible  to  utilize  this  process 
for  hardening  parts  which  were  subject  to  much  wear  and  little 
strain?  Explain  procedure. 

(b)  Why  is  it  necessary  to  preheat  such  pieces  as  the  following  before 
the  weld  is  attempted;  broken  water-jackets  on  gas-engine  cylinders, 
usually  brought  about  by  freezing,  and  holes  or  cracks  in  crank 
cases,  caused  by  the  loosening  of  a  connection  rod;  when  lugs  on  the  same 
cylinder,  the  arms  on  the  same  crank  case  can  be  welded  without  pre- 
heating, and  ofttimes  without  even  dismantling  the  motor? 


LECTURE  NUMBER  FIVE 

Subject — WELDING  OF  CAST  IRON 

(Part  Three) 

14.  Describe  fully  the  manner  in  which  two  cast-iron  bars  measuring 
i  X6  inches  and  24  inches  long,  are  welded  end  to  end,  citing  preparations, 
precautions,  and  the  procedure  and  materials  necessary  to  execute  and 
carry  the  weld  through  to  a  cool  state. 

NOTE. — Both  gases  are  in  the  line  hoses  as  far  as  the  welding  torch. 

LECTURE  NUMBER  SIX 
Subject — WELDING  or  CAST  IRON 
(Part  Four) 

15.  (a)  Are  water  jackets  on  cast-iron  cylinder  blocks  welded  in  a 
cold,  or  a  preheated  condition? 

(b)  Is  this  true  under  all  conditions? 

(c)  If  a  crack  were  found  in  the  combustion  head  of  a  cylinder  block 
and  the  entire  water  jacket  and  cylinder  were  cast  in  one,  how  should  this 
job  be  prepared  in  order  to  make  a  successful  weld? 

(d)  In  welding  a  broken  lug  on  the  base  of  a  cylinder  block  how  should 
lug  appear  after  weld  is  cold? 


154  LECTURES 

LECTURE  NUMBER  SEVEN 

Subject — EQUIPMENT 

1.  Describe  the  operation,  step  by  step,  taken  to  set  up  an  oxy- 
acetylene  welding  plant,  from  the  assembling  of  the  parts,  right  through, 
until  a  neutral  welding  flame  is  obtained.     (If  a  sketch,  with  the  gas 
cylinders  and  parts  numbered  i,  2,  3,  etc.,  will  assist  in  making  descrip- 
tion clear,  it  may  be  used.) 

2.  (a)  Is  it  desirable  to  have  a  planed  metal,  or  a  brick-top  table  for 
welding  purposes? 

(6)  Explain  why. 

3.  Outline  and  describe  briefly,  a  simple  method  of  building  a  popular 
type  of  welding  table. 

4.  (a)  What  is  the  name  and  style  of  bricks  used  in  the  welding  shop? 
(b)  Name  at  least  three  purposes  for  which  these  bricks  are  used. 

5.  (a)  Why  does  an  emery  wheel  play  such  an  important  part  in  the 
oxy-acetylene  welding  industry? 

(b)  Why  is  it  desirable  to  have  a  flexible  shaft  attachment  for  the 
emery  wheel,  if  possible? 

(c)  Name  some  of  the  important  things  a  flexible  shaft  attachment 
is  used  for  in  the  preparation  and  finishing  of  welds. 

6.  (a)  In  what  kind  of  containers  is  retort  cement  purchased  in  the 
commercial  world? 

(b)  Where  is  retort  cement  used  in  the  welding  shop? 

(c)  How  does  it  differ  from  the  ordinary  clay  or  putty? 

7.  (a)  Why  should  a  blacksmith  forge  be  added  to  the  welding 
shop  equipment  if  one  is  obtainable? 

(b)  What  two  important  tasks  is  a  forge  used  for  in  the  welding 
shop? 

8.  (a)  It  is  essential  that  several  pails  of  water  be  located  throughout 
the  shop;  why  should  this  be  necessary? 

(b)  Mention  a  few  instances  where  water  is  required  in  the  welding 
shop. 

9.  Explain  fully  why  great  care  should  be  exercised  in  ventilating  a 
shop  where  commercial  welding  is  being  done. 

10.  (a)  Describe  one  simple  method  of  constructing  a  flux  box. 
(b)  What  advantages  has  this  type  of  container? 


LECTURES  155 

LECTURE  NUMBER  EIGHT 
Subject — REPAIRS 

1.  What  is  the  best  method  of  locating  a  leak  in  either  the  oxygen  or 
acetylene  lines? 

2.  If  a  leak  were  found  in  a  ground  seat,  how  could  it  be  stopped  if 
the  nut  on  the  coupling  had  been  screwed  up  as  far  as  possible? 

3.  Name  one  method  of  attaching  connections  to  hoses  so  that  tkey 
will  not  blow  off  or  pull  off  when  pressure  is  applied. 

4.  How  could  either  an  oxygen  or  acetylene  hose  that  had  been 
burned  or  otherwise  injured,  be  repaired  to  withstand  the  gas  pressure? 

5.  How  could  regulator  be  operated  if  the  cross-bar  for  applying  pres- 
sure upon  the  diaphragm  springs  were  lost? 

6.  (a)  What  procedure  would  be  necessary  to  make  connection  if 
cylinder  were  supplied  with  an  adaptor  which  would  not  fit  the  regulator 
connection  and  it  could  not  be  coupled  up  directly? 

(b)  Realizing  that  all  cylinder  connections  about  a  regulator  are  gen- 
erally supplied  with  a  ^-inch  taper  pipe  thread,  why  do  all  manufacturers 
solder  them  in? 

7.  Explain  why  oxygen  high-pressure  gauges  are  constructed  with  a 
loose  back  and  a  solid  front. 

8.  (a)  Where  is  the  first  place  to  seek  trouble  in  a  gauge  if  it  leaks? 

(b)  Can  such  leaks  be  repaired? 

(c)  Describe  method. 

9.  If  either  a  high-  or  low-pressure  gauge  were  injured  beyond  the 
repair  state  how  could  welding  plant  be  kept  in  operation  without  it? 

10.  (a)  What  would  be  the  trouble,  in  shutting  off  a  welding  plant, 
if  there  were  a  reading  on  the  high-pressure  gauge  and  none  on  the  low- 
pressure  gauge,  after  permitting  gas  to  escape  from  the  hose? 

(b)  How  could  the  reading  on  this  gauge  be  brought  back  to  zero? 

LECTURE  NUMBER  NINE 

Subject — STEEL  WELDING 
(Part  One) 

1.  (a)  Is  the  welding  of  steel  more  or  less  difficult  than  cast  iron? 
(b)  Explain  why. 

2.  (a)  Why  is  the  choice  of  the  welding  tip  so  important  when  working 
on  steel? 


156  LECTURES 

(b)  What  will  result  if  the  tip  is  too  large? 

(c)  If  too  small? 

3.  (a)  Why  is  the  choice  of  a  "filler-rod"  of  a  correct  size  so  impor- 
tant for  steel  welding? 

(b)  What  will  happen  if  the  "filler-rod"  is  too  large? 

(c)  If  too  small? 

4.  (a)  What  kind  of  a  "filler-rod"  is  used  in  welding  steel? 

(b)  Give  a  general  rule  covering  relation  of  "filler-rod"  to  the  metal 
being  welded  in  all  cases,  but  one  or  two. 

(c)  Name  one  exception. 

5.  (a)  Is  a  flux  (or  scaling  powder)  necessary  in  welding  steel? 
(b)  Explain  why. 

6.  (a)  How  is  the  flame  adjusted  for  steel  welding? 

(b)  What  kind  of  a  flame  is  generally  used  in  finishing  steel  work? 

(c)  Why  is  this  done? 

7.  (a)  How  is  the  flame  held  when  executing  a  steel  weld? 
(6)  How  is  the  "filler-rod"  held  when  making  a  steel  weld? 

8.  (a)  Is  it  necessary  to  "V"  out  on  steel  the  same  as  on  cast  iron? 
(b)  Explain  why. 

9.  (a)  Is  a  steel  weld  as  strong  as  the  original  metal  if  not  built  up? 
(b)  Explain  why. 

10.  (a)  Is  the  same  provision  made  for  expansion  and  contraction 
on  steel  as  on  cast  iron? 

(b)  Give  reasons  for  so  thmking. 


LECTURE  NUMBER  TEN 

Subject — STEEL  WELDING 
(Part  Two} 

11.  (a)  What  is  meant  by  a  "crater"  in  steel  welding? 
(6)  How  are  they  removed  from  the  weld? 

12.  (a)  What  are  some  methods  and  marks  of  distinguishing  steel 
from  other  metals? 

(b)  How  is  cast  steel  distinguished  from  cast  iron? 

13.  (a)  Name  some  of  the  qualifications  of  a  good  "filler-rod"  for 
mild  steel  welding. 

(b)  In  what  manner  does  the  "filler-rod"  differ  for  the  alloyed  and 
high-carbon  steels? 

14.  (a)  In  bringing  the  neutral  flame  in  contact  with  the  metal  on  a 


LECTURES  157 

steel  weld,  should  the  cone  bend  and  spread  on  the  surface,  or  just 
lick  it? 

(b)  Explain  why. 

15.  (a)  What  is  the  principal  cause  for  hard  spots  in  steel  welds? 
(b)  What  causes  some  of  the  others? 

16.  (a)  Is  it  rolled  steel  or  cast  steel  that  does  not  expand  when 
heated? 

(b)  Name  one  other  metal  that  does  not  expand  when  heated. 

17.  (a)  Why  are  welds  more  difficult  on  sheet  iron  and  steel  than  on 
some  of  the  heavier  pieces? 

(b)  What  can  be  used  as  a  "filler-rod"  on  sheet  metal  work? 

18.  (a)  What  difficulty  is  generally  encountered,  when  making  a 
long  weld  like  on  a  steel  tank? 

(b)  How  can  this  be  overcome? 

(c)  Why  do  the  open  ends  on  sheet  steel  welds  overlap  in  welding 
when  same  class  of  work  on  cast  iron  separates? 

19.  (a)  What  causes  steel  welds  to  carbonize? 
(6)  What  usually  causes  a  burnt  steel  weld? 

20.  Describe  fully  how  a  broken  automobile  frame  can  be  welded 
and  re-enforced  to  make  it  stronger  than  originally. 


LECTURE  NUMBER  ELEVEN  f 

Subject — STEEL  WELDING 
(Part  Three) 

21.  (a)  What  kind  of  a  "filler-rod"  is  used  in  welamg  cast  steel? 
(b)  Is  a  flux  used? 

22.  (a)  What  kind  of  a  "filler-rod"  is  employed  when  welding  cast 
iron  to  steel? 

(b)  What  kind  of  a  flux  is  used? 

23.  (a)  Can  springs  be  successfully  welded? 
(b)  State  reasons. 

24.  (a)  Why  are  crank-shaft  welds  so  hard  to  execute  successfully? 

(b)  What  kind  of  a  "filler-rod"  is  used  for  best  results  on  most 
crank-shafts? 

(c)  What  points  does  the  welder  consider  when  deciding  whether  a 
weld  of  this  nature  is  advisable? 

25.  (a)  Briefly  describe  the  method  of  building  up  crank-shaft  bear- 
ings that  have  been  worn  down. 


158  LECTURES 

(b)  What  are  some  of  the  precautions  taken  in  work  of  this  kind? 

26.  (a)  When  automobile  propeller  shafts  and  rear  axles  break,  it  is 
generally  adjoining  the  square  end.     Is  it  advisiable  to  weld  this  short 
piece  on? 

(b)  What  is  the  correct  procedure  in  a  case  of  this  kind? 

27.  (a)  If  a  case-hardened  ring-gear  is  to  have  its  teeth  built  up  or 
new  ones  added,  how  is  it  handled  after  welding? 

(b)  Should  all  case-hardened  work  be  so  treated  after  welding? 

28.  (a)  In  welding  two  pieces  of  metal,  one  of  which  is  considerably 
lighter  than  the  other,  how  is  the  flame  held  in  order  to  bring  both  pieces 
to  a  fusion  at  the  same  time? 

29.  (a)  If  a  steel  weld  were  to  break  in  the  line  of  weld,  how  should  it 
be  prepared  if  it  is  to  be  rewelded? 

(b)  Does  this  procedure  apply  only  to  steel? 

30.  Were  a  hole  6  inches  square  in  a  sheet  of  steel  to  be  welded  up 
without  preheating,  what  would  be  the  approximate  size  of  the  patch 
necessary  and  how  would  it  be  prepared,  in  order  to  take  care  of  the  expan- 
sion and  contraction  strains? 


LECTURE  NUMBER  TWELVE 
Subject — STEEL  WELDING 
(Part  Four) 

li.  (a)  Why  should  a  steel  weld  of  any  kind  be  executed  as  rapidly 
as  possible? 

(b}  What  will  happen  if  steel  is  kept  in  a  heated  condition  too  long? 
(c)  Why  should  a  change  be  in  evidence  under  these  conditions? 

32.  (a)  Explain  what  is  meant  by  a  "dished"  patch,  for  boiler  or 
thin  armor  plate? 

(b)  Draw  such  a  patch. 

(c)  How  is  a  patch  of  this  nature  prepared? 

33.  (a)  What  is  meant  by  a  "corrugated"  patch  for  boiler  or  thin 
armor  plate? 

(b}  Sketch  such  a  patch. 

(c)  How  is  this  kind  of  a  patch  prepared? 

34.  (a)  What  advantages  has  a  "corrugated"  patch  over  one  that  is 
"dished"? 

(b)  Where  are  "corrugated"  patches  used  extensively? 

35.  (a)  How  are  boiler  flues  prepared  for  re-tipping? 


LECTURES  159 

(b)  Sketch  a  simple  jig  for  holding  such  pieces  in  place  for  welding. 

36.  (a)  Describe  how  lengths  of  various  sized  pipe  can  be  welded 
together  end  to  end. 

(b)  What  precautions  are  necessary  when  executing  such  welds? 

37.  (a)  When  welding  large  steel  castings  why  is  it  almost  always 
advisable  to  preheat  the  work? 

(&)  Why  is  preheating  so  necessary  on  vanadium  and  other  alloyed 
steels? 

38.  Why  is  it  desirable  to  chip  out  the  sand  and  thin  scale  formations, 
in  and  around  blow-holes  in  steel  castings  before  filling  in? 

39.  (a)  Why  do  the  majority  of  good  welders  bend  their  steel  "filler- 
rods"  at  right  angles  about  6  inches  from  the  end? 

(b)  Why  isn't  this  being  done  on  cast  iron? 

40.  (a)  What  advantage  is  there  in  making  a  vertical  weld  from  the 
top  down,  rather  than  starting  from  the  bottom  and  working  up? 

(b)  In  welding  overhead  why  is  it  so  important  that  the  work  be  in  a 
molten  state  before  adding  the  "filler-rod"? 

(c)  In  overhead  welding,  why  doesn't  the  metal  drop  when  in  a  molten 
state? 

LECTURE  NUMBER  THIRTEEN 

Subject— OXY-ACETYLENE   CUTTING 

1.  Explain  fully  which  parts  of  an  oxy-acetylene  cutting  plant  are 
different  from  a  welding  unit. 

2.  (a)  If  there  is  a  difference  in  either  of  the  regulators,  mention 
which  one  it  is. 

(b}  What  is  the  difference? 
(c)  Why  is  it  necessary? 

3.  (a)  Is  it  possible  to  weld  with  a  cutting  torch? 

(b)  What  precaution  is  necessary  if  this  is  done? 

(c)  Why  isn't  this  process  used? 

4>  Explain  how  cutting  can  be  done  with  the  welding  torch  if  neces- 
sary. 

5.  (a)  In   cutting  by   the  oxy-acetylene  process,   which  does  the 
cutting,  the  oxygen  jet  or  the  neutral  flame? 

(6)  What  action  has  the  oxygen  jet  on  the  metal? 
(c}  What  part  does  the  neutral  flame  play  in  cutting? 

6.  Can  oxygen  or  acetylene  under  sufficient  pressure  be  made  to  cut . 
individually?     Explain  fully. 


160  LECTURES 

7.  Why  is  it  specially  important  that  armored  hose  be  used  on  the 
oxygen  line  when  making  heavy  cuts? 

(Give  at  least  two  reasons.) 

8.  (a)  How  is  a  cutting  torch  lighted?    Describe  in  detail. 
(b}  How  is  cut  started  on  metal? 

(c)  How  is  torch  held  in  regard  to  metal  being  cut? 

9.  (a)  Is  it  possible  to  successfully  cut  cast  iron? 

(b)  Wrought  iron? 

(c)  Cast  steel? 

(d)  Rolled  steel? 

10.  (a)  Cutting  can  be  done  under  water  with  ordinary  cutting  appa- 
ratus; why  doesn't  the  flame  go  out  when  submerged? 

(b)  What  additional  equipment  is  generally  used  in  underwater 
cutting? 


LECTURE  NUMBER  FOURTEEN 
Subject — BRASS  WELDING 

1.  Explain  as  fully  as  possible  the  chief  characteristics  of  a  good 
"filler-rod"  for  brass  welding. 

2.  (a)  Is  a  flux  used  in  welding  brass? 

(b)  What  is  one  way  of  making  a  good  flux  for  brass? 

3.  (a)  What  kind  of  a  flame  is  used  in  brass  welding? 
(b)  Why? 

4.  (a)  In  what  position  is  the  flame  held  in  welding  brass? 
(b}  How  should  the  "filler-rod"  be  held? 

5.  (a)  Is  it  advisable  to  "  V"  out  or  burn  off  the  ends  of  brass  work  to 
be  welded? 

(b)  Explain  why. 

6.  (a)  What  causes  the  dense  white  fumes  to  appear  when  fusing 
brass? 

(b)  What  is  cause  of  brass  welds  being  porous? 

7.  Why  should  brass  work  not  be  disturbed  when  red  hot? 

8.  What  is  the  most  difficult  part  of  brass  welding  as  a  whole? 

9.  Why  are  brass  welds  generally  cooled  in  water  as  soon  as  fusion  is 
completed? 

10.  Why  is  it  difficult  for  the  beginner  to  weld  heavy  pieces  of 
brass? 


LECTURES  161 

LECTURE  NUMBER  FIFTEEN 
Subject — WELDING  OF  MALLEABLE  IRON 

1.  (a)  Can  malleable  iron  be  successfully  welded? 

(b)  What  is  the  most  successful  method  of  joining  two  pieces  of  malle- 
able iron? 

2.  What  are  three  methods  of  detecting  malleable  iron? 

3.  (a)  What  kind  of  "filler-rod"  is  used  on  malleable  iron? 

(b)  Are  "  filler-rods  "  of  malleable  iron  satisfactory? 

(c)  What  kind  of  flux  is  used  on  malleable  iron  work? 

4.  (a)  How  is  a  malleable  iron  casting  prepared  for  welding? 

(b)  How  hot  should  work  be,  previous  to  adding  "filler-rod"? 

(c)  What  will  occur  if  too  much  heat  is  applied? 

5.  (a)  In  what  respect  does  the  adjustment  of  the  flame  differ  on 
malleable  iron  from  that  of  cast  iron  and  steel? 

(b)  How  is  the  flame  held  in  relation  to  the  work? 

(c)  Does  the  flame  come  in  direct  contact  with  the  "filler-rod"? 

6.  (a)  Is  more,  or  less,  surface  covered  by  the  "filler-rod"  on  malle- 
able iron  than  on  cast  iron? 

(b)  Why? 

7.  (a)  How  should  malleable  iron  be  cooled? 
(b)  Is  this  the  same  as  in  welding  brass? 

8.  On  what  part  of  machinery  does  a  welder  generally  expect  to  find 
malleable  iron  castings? 

9.  Explain  carefully  how  a  malleable  iron  automobile,  axle  or  trans- 
mission, housing  that  has  been  cracked  or  broken,  can  be  re-enforced 
so  that  it  will  be  stronger  than  ever. 

10.  Describe  very  briefly  how  malleable  iron  is  made  and  in  what 
respect  it  differs  from  cast  iron  when  cold,  and  also  when  under  the  influ- 
ence of  the  oxy-acetylene  flame. 

LECTURE  NUMBER  SIXTEEN 
Subject — CARBON  BURNING 

1.  (a)  Explain  what  is  meant  by  carbon  burning. 
(b)  In  what  respect  is  it  used  extensively? 

2.  (a)  Will  oxygen  gas  burn  alone  or  does  it  merely  aid  combustion? 
(b)  Will  carbon  in  a  free  state  burn? 

3.  (a)  Why  is  it  advisable  to  remove  only  the  spark  plugs  and  not 


162  LECTURES 

the   entire  valve    cap  or  "bonnet"  when  burning   carbon    in   a  gas 
engine? 

(b)  Can  it  be  done  either  way? 

4.  (a)  Does  it  make  a  difference  if  the  carbon  is  hard  and  dry  in  the 
cylinder? 

(b)  What  will  help  in  such  cases? 

5.  (a)  If  the  cylinder  is  rather  oily  does  this  make  a  difference? 
(b)  Does  the  presence  of  oil  aid  or  retard  combustion? 

6.  (a)  What  precautions  are  necessary  before  carbon  burning  is 
attempted? 

(b)  How  is  asbestos  paper  used  in  carbon  burning? 

(c)  Name  a  good  substitute  for  asbestos  paper  when  carbon  burning. 

7.  (a)  Is  there  any  danger  of  warping  the  valves  and  overheating  the 
cylinder  and  piston  when  burning  carbon? 

(b)  What  is  the  effect  of  carbon  burning  on  aluminum  pistons? 

8.  (a)  What  pressure  is  used  on  the  oxygen  line  for  carbon  burning? 
(b)  Will  carbon  burning  re-grind  valves? 

9.  (a)  How  long  should  the  burning  be  done? 

(b)  How  often  is  carbon  burning  recommended  for  a  gas  engine? 

(c)  If  there  are  any  carbon  particles  or  sand  left  in  the  cylinder  after 
burning  is  done  how  are  they  removed? 

10.  Describe  how  the  carbon  is  removed  from  a  four-cylinder  engine, 
paying  particular  attention  to  details  such  as  lighting,  which  part  of  the 
head  the  torch  is  played  on  first,  what  does  the  burning  and  where  the 
carbon  goes. 


LECTURE  NUMBER  SEVENTEEN 
Subject — PREHEATING  AGENCIES 

1.  (a)  What  is  meant  by  preheating  as  applied  to  the  oxy-acetylene 
welding  industry? 

(b}  What  are  several  fuels  which  can  be  used  very  successfully  for 
preheating? 

2.  Name  the  three  principal  reasons  why  parts  to  be  welded  are  gen- 
erally preheated. 

3.  (a)  Why  is  charcoal  considered  the  best  preheating  agent  for  gen- 
eral welding? 

(b}  Why  should  it  not  be  used  to  any  great  extent  in  closed  rooms  dur- 
ing the  winter  months? 


LECTURES  163 

(c)  If  used  during  the  winter  what  precautions  are  observed? 

4.  (a)  Mention  two  materials  which  are  used  extensively  for  building 
up  ovens  and  doing  the  preheating. 

(b)  What  kind  of  brick  is  used? 

5.  (a)  How  much  should  cast  iron  be  preheated? 

(b)  Brass  or  bronze? 

(c)  Aluminum? 

6.  Sketch  and  describe  how  a  temporary  brick  preheating  oven  should 
be  built,  giving  all  dimensions,  such  as:   length,  width  and  height  and 
reasons  for  them. 

7.  Explain  how  a  cylinder  block  with  a  broken  water  jacket  is  set 
up  for  preheating;  how  oven  is  built  for  charcoal  fire;  how  fire  is  started ; 
how  block  is  protected  while  welding  and  how  it  is  returned  to  a  cold 
state. 

8.  (a)  What  precautions  are  necessary  in  setting  up  and  preheating 
aluminum? 

(b)  If  piece  is  to  be  turned  while  in  the  fire,  what  provision  is  made  in 
building  up  oven? 

9.  In  which  cases  is  preheating  absolutely  necessary  in  order  to  make 
a  satisfactory  weld? 

10.  (a)  Give  a  sketch  showing  a  preheating  torch  for  use  on  illuminat- 
ing gas  and  compressed  air,  which  can  be  constructed  very  easily. 

(b)  Why  are  preheating  torches  not  popular  for  general  welding? 

(c)  Where  are  they  used  in  numbers? 

LECTURE  NUMBER  EIGHTEEN 
Subject — ALUMINUM  WELDING 
(Part  One) 

1.  (a)  Is  the  welding  of  aluminum,  more  or  less  difficult  than  such 
metals  as  cast  iron  and  steel? 

(b)  Explain  why. 

2.  (a)  Name  the  two  methods  of  making  aluminum  welds. 

(b)  Can  they  be  combined? 

(c)  Why? 

3.  (a)  What  kind  of  a  "filler-rod"  is  used  in  welding  aluminum? 
(b)  Is  a  flux  used?     Why? 

4.  (a)  Is  a  cast  or  drawn  "  filler-rod  "  preferred? 

(b)  Name  the  two  important  metals  which  should  be  present  and  the 
percentage  of  each  in  the  "filler-rod." 


164  LECTURES 

5.  (a)  How  should  the  flame  be  adjusted  for  aluminum  welding? 
(b)  How  is  the  flame  held  in  relation  to  the  work? 

6.  (a)  How  is  the  "filler-rod"  added? 

(b)  In  what  respect  does  this  differ  from  all  other  metals? 

(c)  Why  can  this  be  done? 

7.  (a)  Name  the  principal  characteristics  of  aluminum  with  regard 
to  heat. 

(b}  What  other  metal  acts  in  a  similar  manner? 

8.  (a)  Is  it  necessary  to  "V"  out  aluminum  for  the  same  reasons  as 
other  metals? 

(6)  Explain  why. 

9.  (a)  Will  an  aluminum  welding  be  as  strong  as  the  original? 
(b}  Give  reasons. 

10.  (a)  What  kind  of  a  tool  is  used  to  aid  in  making  an  aluminum 
weld  by  most  welders? 

(6)  How  is  such  a  tool  made? 


LECTURE  NUMBER  NINETEEN 

Subject — ALUMINUM  WELDING 
(Part  Two) 

11.  (a)  What  kind  of  files  are  used  to  finish  aluminum  welds? 
(b)  In  what  respect  do  they  differ  from  the  ordinary  kind? 

12.  (a)  In  which  hand  is  the  welding  torch  held  in  aluminum  work? 

(b)  In  which,  the  "filler-rod'"? 

(c)  The  puddle  stick? 

13.  (a)  What  materials  are  used  to  "back-up"  aluminum  work  for 
preheating? 

(b)  Describe  fully  how  aluminum  is  "backed-up"  previous  to  pre- 
heating, in  order  to  prevent  the  collapse  of  metal  while  welding. 

14.  (a)  How  quick  does  the  heavy  coating  or  aluminum  oxide  form 
on  a  clean  hot  piece  of  aluminum? 

(b)  Will  the  metal  flow  together  when  this  oxide  is  present? 

(c)  How  is  it  overcome? 

15.  (a)  Is  it  advisable  to  weld  aluminum  from  one  side  only  or  from 
both  sides? 

(b)  Why? 

16.  In  preheating  aluminum  with  charcoal,  what  precautions  are 


LECTURES  165 

taken  in  setting  up;  in  starting  the  fire;   during  the  welding  operation, 
and  in  cooling  the  piece? 

17.  (a)  Are  preheating  torches  played  directly  on  aluminum  work? 
(b)  What  kind  of  an  oven  is  used? 

1 8.  (a)  Is  it  necessary  to  heat  the  whole  of  an  aluminum  crank-case 
if  one  part  has  to  be  preheated? 

(b)  Give  reasons. 

19.  (a)  Are  clamps  used  to  hold  parts  in  place  on  preheated  aluminum? 
(b)  Explain  why.  t 

20.  When  starting  to  weld  a  cold  piece  of  aluminum,  the  flame  is 
brought  in  contact  with  the  work  and  held  there  much  longer  than  on  a 
similar  size  piece  of  steel  before  any  apparent  change  occurs.  •  How  is 
this  accounted  for,  knowing  that  aluminum  has  a  much  lower  melting 
point  that  steel? 


LECTURE  NUMBER  TWENTY 

Subject — ALUMINUM  WELDING 

(Part  Three) 

21.  Explain   fully  why  it   is   necessary   to    employ   greater   speed 
in  the  welding  of  aluminum  than  on  any  other  metal? 

22.  (a)  What  is  retort  cement? 

(b}  How  does  it  differ  from  ordinary  clay? 

(c)  For  what  purpose  is  it  used  in  aluminum  welding? 

23.  (a)  When  performing  an  aluminum  weld  by  the  puddle  system, 
is  the  welder  dependent  upon  the  flame,   the  "filler-rod"  or  the  puddle 
stick,  for  the  fusion  of  the  metal? 

(b)  Give  explanations. 

24.  (a)  What  method  of  welding  is  used  when  executing  a  vertical 
weld  on  aluminum? 

(b)  Why  isn't  the  other  method  used? 

(c)  Is  the  vertical  welding  of  aluminum  to  be  avoided? 

25.  (a)  Can  aluminum  welds  be  made  overhead? 
(b)  Explain  why. 

26.  (a)  Is  the  same  method  used  on  aluminum  as  in  cast  iron  in 
welding  from  the  closed  end,  toward  the  open? 

(b)  Is  this  procedure  necessary  on  preheated  work? 

27.  (a)  If  a  suspension  arm,  of  a  "U"  type,  on  an  aluminum  crank 


166  LECTURES 

case  were  to  break  about  3  or  4  inches  from  the  body  of  the  case,  could  it 
be  welded  in  place  without  dismantling  the  motor? 

(b)  Explain  in  detail  how  such  an  arm  should  be  welded. 

28.  Due  to  the  contraction  and  expansion,  it  is  very   difficult  to 
have  the  bolt  hole,  in  the  end  of  an  aluminum  suspension  arm  that  has 
been  welded,  return  exactly  to  its  former  position.    How  is  this  diffi- 
culty provided  for? 

29.  (a)  Should  a  section  of  an  aluminum  crank  case  be  missing,  would 
it  be  advisable  to  build  up  a  new  part  with  the  "filler-rod"  or  to  cast  a 
new  part  in  a  mold  and  then  weld  it  in? 

(b)  Under  what  conditions  should  the  above  be  done? 

30.  (a)  If  it  were  found  that  an  aluminum  crank  case  after  being 
welded,  had  one  corner  about  f-inch  lower  than  the  rest  of  the  case  and 
it  had  not  affected  any  of  the  bearings,  could  it  still  be  reclaimed? 

(b)  Give  procedure. 


INDEX 


Absorbent,  acetone  as  an,  26,  31 

—  asbestos  as  an,  31 

—  charcoal  as  an,  31 

—  mineral  wool  as,  81 
Acetone  as  an  absorbent,  26,  31 
Acetylene  cylinders,  construction  of, 

3i 
Acetylene  gas,  temperature  of  flame 

of,  i 

Adapter,  types  of,  46 
Aluminum,  backing  up  in  welding,  114 

—  charcoal  in  welding,  116 

—  contraction     and     expansion     in 

welding,  116 

—  clamps,  use  of  in  welding,  115 

—  crank  cases,  welding,  118 

—  filler-rods  in  welding,  112,  115 

—  flux  method  of  welding,  109,  in 

—  oxidation    of    bright    surfaces    in 

welding,  113 

—  preheating  in  welding,  1 16, 117 

—  preheating,  method  of,  52 

—  puddle     and     flux     systems     of 

welding  compared,  1 1 1 

—  puddle  method  of  welding,  109,  in 

—  strains,  avoiding  internal,  118 

—  suspension    arm    of    crank    case, 

repairing,  118 

—  tip  used  in  welding,  109 

—  welding,  109-117 

—  welding  from  one  side,  1 14 
Apparatus,  classes  of  welding,  19 

—  desirability  of  securing  the  best, 

144 


Apparatus,  emery  wheel,  need  of,  41 

—  high-pressure  welding,  20 

—  low-pressure  welding,  19 

—  medium-pressure  welding,  19 

—  metal    top    table,    disadvantages 

of,  39 

—  mixing  chambers,  21 

—  oils  and  grease  to  be  avoided,  37 

—  oxy-acetylene,  for  cutting,  125 

—  regulator,  22 
-  types  of,  24 

—  required  in  welding,  19-26 

—  replacing  lost  cross-bar,  46 

—  setting  up,  manner  of,  31,  32 

—  shop  equipment,  39,  43 

—  shutting  off,  procedure  in,  35 
Apparatus  repairs,  44-50 

—  adapters,  types  of,  46 

—  gauges,  operation  of,  49 

—  gauges,  safety,  47,  48 

—  hose  clamps,  45 

—  hose,  repairing  leaky,  45 

—  leaks,  method  of  locating,  44 

—  leaky  threads,  repairing,  44 
Asbestos  as  an  absorbent,  31 

—  in  aluminum  welding,  116 

—  paper  cover  protection,  55 
Automobile  frame,  welding,  91 
Automobile,  propeller  shafts,  welding, 

95 
Axles,  automobile,  welding,  95 

B 

Blow  holes,  causes  of,  65 
Boiler  flues  retipping,  98,  99 


167 


168 


INDEX 


Boiler,  "corrugated"  patches,  102, 103 

—  "dished"  patches  in  repairs  to,  101 

—  "L"  patches  in  repairing,  103 

—  repairing,  99-101 
Borax  as  a  brass  flux,  107 
Brass,  alloy  of,  106 

—  filler-rod  in  welding,  106 

—  flux  in  welding,  107 

—  fumes  in  welding,  108 

—  melting-point,  106 
Brass  welding,  106-108 
Bronze  for  welding  purposes,  123 

—  welding  malleable  iron  with,  121 


Carbon  burning,  135-144 

—  in  gasoline  engine,  136-139 

—  theory  of,  139 
Carbonizing  flame,  34 
Cast  iron,  welding  of,  58-80 

—  blow  holes,  causes  of,  65 

—  charcoal     as     preheating 

agent,  76 

—  combustion  head  of  cyl- 

inder, repairing,  78,  79 

contraction  of  metals  in, 

prevention  of,  71 

expansion    and    contrac- 
tion of  metals,  65-67 

—  filler  rod,  61 

—  flux  a  cleansing  agent,  61 

—  flux,  manner  of  applica- 

tion of,  62 

—  flux,     simple     substitute 

for,  6 1 

—  gasoline    engine    cylinder 

block,  repairing,  75,  76 

—  gear    wheel    teeth,    three 

ways       of       restoring, 
broken,  71-74 

hardening  parts  by  use  of 

carbonizing  flame,  74 

—  lugs,  welding  on  cylinder 

block,  80 


Cast  iron,  welding  of,  methods  of 
distinguishing  metals, 
60 

—  preparations  for,  67 

—  procedure  in,  63,  64,  67-70 

—  successful  weld,  criterion 

of,  75 

—  tip,  size  of,  63 

Cast  steel,  procedure  in  welding  of,  88 
Charcoal  as  an  absorbent,  31 

—  as  preheating  agent,  76 

—  in  aluminum  welding,  116 
Clamps,  inadvisable  in  welding  alum- 
inum, 115 

Contraction  and  expansion  in  alum- 
inum welding,  116 
—  in  preheating,  53 

in  welding  steel,  87 

Contraction  of  metal  in  welding,  pre- 
vention of,  71 

"Corrugated"  patch,  method  of  mak- 
ing, 102,  103 

Crank  cases,  aluminum,  repairing,  118 
Crank  shafts,  welding  methods,  93,  94 
Crater,  development  and  removal  of, 

88 

Cross-bar,  replacing  lost,  46 
Cutting  by  oxy-acetylene  process,  6 
Cutting  with  oxy-acetylene,  125-134 
Cutting    torch,    welding    torch    and, 

compared,  127 
Cylinder    block,   repairing    cast-iron 

gasoline  engine,  75,  76 
Cylinder  bore,  device  for  polishing, 

79,80 
Cylinders,  acetone  as  absorbent  in,  26 


Decarbonization    of   automobile   en- 
gines, 136,  139 
Demand  for  oxy-acetylene  operators, 

17 
"Dished"  patch  in  boiler  repairs,  101 


INDEX 


169 


E 

Emery  wheel,  value  of  in  welding 

shop,  41 
Expansion  and  contraction  of  metals, 

65-67 

—  in  welding,  87 
Explosions,  precautions  against,  37 


F 


Feather  flame,  33,  35 
Filler  rod,  89 

—  in  brass  welding,  106 

—  in  welding  malleable  iron,  122 

—  metal  in,  61 

—  used  in  aluminum  welding,  112 

—  used  in  welding  steel,  82,  91 
Fire  brick,  in  aluminum  welding,  116 

—  preheating  oven  of,  54 

—  table,  39 
Flame,  carbonizing,  34 

—  feather,  33,  35 

—  neutral  33, 35 

—  oxidizing,  34 

—  torch,  cutting  under  water  with, 

133 

—  varieties  of,  adjustment  of,  32, 33 
Flashbacks,  causes  of,  21,  22 

—  prevention  of,  22 

Flux,  application,  manner  of,  62 

—  container,  42 

—  in  brass  welding,  107 

—  office  of,  6 1 

—  substitute,  a  simple  and  effective, 

61 


Gasoline    engine,    carbon,    how    to 

remove  from,  136-139 
Gasoline  tanks,  necessity  for  caution 

in  repairing,  103 
Gauges,  operation  of,  49 
—  safety,  47, 48 


Gear    wheel    teeth,    three    ways    of 

restoring  broken,  71-74 
Glossary,  145-148 
Goggles,  eye,  35 


Hardening  parts  through  use  of  car- 
bonizing flames,  74 
Heat  in  welding  malleable  iron,  123 
High-pressure  regulated,  24 
Hose,  armored,  used  on  oxygen  line, 

133 

—  clamps  in  reparing,  45 
-  leaky,  45 

L 

"  L  "  patches,  103 
Leaks,  method  of  discovering,  44 

—  repairing  threads,  44 
Lectures,  149-166 
Low-pressure  regulator,  24 

Lugs,  welding  on  cylinder  block,  80 

M 

"Maine,"  battleship,  wreck  cut    up 

with  oxy-acetylene  gas,  6 
Malleable  iron,  bronze,  welding  with, 
121,  123 

—  clean   surface,  necessity   of  in 

welding,  122 

—  heat  in  welding,  123 

—  melting  to  be  avoided,  121 

—  preheating  unusual,  123 

steel  strips  in  welding,  1 23 

welding,  1 20-1 24 

Metals,    methods   of   distinguishing, 

60,87 

Mineral  wool  as  an  absorbent,  31 
Mixing  chamber,  21 

N 

Needle  valve,  regrinding  leaky,  26 
Neutral  flame,  33,  35 


170 


INDEX 


Oils  and  grease,  importance  of  avoid- 
ing use  of,  37 

Operation  in  oxy-acetylene  welding, 
27-38 

Operator,  standing  position  of,  re- 
lative to  work,  32 

Overhead  welding,  105 

Oxidation  of  bright  surfaces  in  alumi- 
num, 113 

Oxidizing  flame,  34 

Oxy-acetylene,  cutting  metals  with, 
6 

—  flame,  varieties  of  adjustment  of, 

32,33 

—  in  airplane  construction,  9 

—  in  automobile  manufacture,   10 

—  in  boiler  shops,  10 

—  in  brass  and  copper  work,  10 

—  in  commercial  welding,  1 1 

—  in  electric  railways,  1 1 

—  in  foundries,  1 1 

—  in  lead  burning,  12 

—  in  lumber  mills,  12 

—  in  machine  shops,  12 

—  in  manufacturing,  12 

—  in  mines,  13 

—  in  pipe  work,  13 

—  in  plate  welding,  13 

—  in  power  plants,  13 

—  in  railroad  work,  13 

—  in  rolling  mills,  14 

—  in  sheet  metal  manufacture,  15 

—  in  shipyards,  15 

—  in  the  forge  shop,  1 1 

—  in  tractor  industry,  16 

—  lake  boats  cut  apart  by,  8 

—  operators,  demand  for,  17 

—  scrap  cut  up  by,  6 

—  scrap  yards,  15 

—  structural  steel,  15 

—  torch  as  fire  department  tool,  7 

—  torch  can  be  used  under  water,  8 

—  varied  uses  of,  9 


Oxy-acetylene  cutting,  125-134 

—  apparatus  for,  1 25 

arrangement  of  oxygen  line,  125 

—  cutting  torch,  extemporizing  a, 

132 

—  flame,  cutting  under  water  with, 

133 

—  flickering  of  oxygen  jet,  127 

—  high-pressure  and  low-pressure 

regulators  compared,  127 

—  hose,  armored,  in,  133 

—  pressure     of     acetylene      and 

oxygen,  129 

—  steel  and  cast-iron,  131 

—  torch  in  preparing  steel,  131 

—  torch,  cutting  and  welding  com- 

pared, 127 

—  torch,  using  cutting,  for  welding 

purposes,  133 

Oxy-acetylene  welding,  apparatus  re- 
quired in, 19-26 

a  fusing  process,  62 

—  auto-frame  repairs,  4 
classes  of  apparatus,  19 

containers,      seamless,      made 

through  use  of,  3 

—  definition  of,  i 

—  fire-brick  table,  39 
future  of,  1 7 

—  growth  of  process,  8 

—  locomotive  frames,  4 

metal-top  table,  disadvantages 

of,  39 

—  mixing  chambers,  21 
operation  in,  27-38 

—  principle  of ,  125 
repairs  through,  3, 5 

—  shop  equipment,  39-43 

—  variety  of  applications  of,  3 
Oxygen,  cylinders,  27 

—  gas,  result  of  too  much,  35 

—  office  of  in  combustion,  27 

—  table    of    different    pressures    of, 

at  various  temperatures,  29 


INDEX 


171 


Preheating,  aluminum,  117 

—  asbestos  paper  for  oven,  55 

—  charcoal  in,  53 

—  extraction  and  expansion  in,  53 

—  drafts,  protecting  work  from,  in,  54 

—  fuels  used  in,  53 

—  in  aluminum  work,  116 

—  ovens,  56 

—  reasons  for,  51 

—  setting  up  work,  56 

—  torch  for,  burning  city  gas,  54 

—  varied  heats  for  different  metals,  52 
Preheating  agencies,  51-57 

—  fire-brick  oven,  54 

—  ovens,  55,  56 

—  torch,  burning  city  gas,  54 
Propeller  shafts,  welding  automobile, 

95 

Puddle  method  of  welding  aluminum, 
109,  in 


R 


Regulator,  care  of,  25 

—  construction  and  action  of,  22,  23 

—  types  of,  24 

Ring  gears,  building  teeth  on  case- 
hardened,  96 
Retort  cement,  42 


Sheet  steel  and  iron,  welding,  89 
Ships,  repairs  to  seized  German  by 

acetylene  process,  5 
Shop  equipment,  39-43 
blacksmith  forge,  42 

carbon  rods  and  blocks,  43 

emery  wheel,  41 

—  fire-brick  table,  39 

—  flux  container,  42 

—  retort  cement,  42 
ventilation,  43 


Sparks,  characteristic  thrown  off  by 

emery  wheel,  59 

Spring's,  welding,  futility  of,  92,  93 
Steel,  automobile  frame,  welding,  91 

—  automobile  axles,  welding  of,  95 

—  automobile      propeller      shafts, 

welding,  95 

—  boiler  flues,  retipping,  98,  99 

—  boiler  repairs,  99-101 

—  cast,  procedure  in  welding,  88 

—  construction    and    expansion     in 

welding,  87 

—  "corrugated"  patch,  102,  103 

—  crank-shafts,  welding  of,  93,  94 

—  craters,  formation  of,  in  welding, 

88 

—  definition,  81 

—  "dished"  patch  in  boiler  repairs, 

101 

—  filler-rod  used  in  welding,  82 

—  filler- rod  to  be  used  in  welding,  97 

—  flame  control  in  welding,  81, 82 

—  hard  spots,  formation  of  in  weld- 

ing, 89 

—  heat    treatment    in    welding    un- 

equal sized  pieces,  97 

—  internal  strains  in  welding,  100 

—  "  L  "  patches,  103 

—  metals,  methods  of  distinguishing 

in  welding,  87 

—  methods  of  welding,  82-86 

—  outside  appearances  in  welding,  87 

—  overhead  welding,  105 

—  sheet,  welding,  89 

—  speed  required  in  welding,  97 

—  springs,  inadvisability  of  welding, 

92,93 

—  susceptibility  of  when  molten,  97 

—  teeth,  building  up  of,  96 

—  vertical  welding  of,  104 

—  weld,   broken,  method  of  repair- 

ing, 96 

—  welding,  difficulties  of,  81, 92 
Steel  welding,  81-105 


172 


INDEX 


Table  of  different  pressures  of  oxygen 
at  various  temperatures,  29 

Tanks  inflammable  gases,  caution  to 
be  used  in  welding,  103 

Teeth,  building  up  of,  96 

Temperature  of  acetylene  gas  flame,  i 

Tip,  size  of  in  welding,  63 


Ventilation,  56,  108 

—  importance  of  in  welding  shop,  43 
Vertical  welding,  104 

"  V-ing  "  metal  in  welding,  63 

W 

Welding,  aluminum,  100-117 

—  brass,  106-108 

—  cast  iron,  procedure,  67-70 

—  malleable  iron,  120-124 


Welding,   methods  of  distinguishing 

between  metals,  58 
—  sparks    in    determining    kind    of 

metals  in,  58 
Welding  of  steel,  81-105 
broken  weld,  manner  of  re- 
pairing, 96 

cast,  procedure  in,  88 

contraction    and    expansion 

in,  87 

crank  shafts,  93, 94 

craters,  formation  of  in,  88 

—  filler-rod  in,  91 

hard    spots,    formation     of 

in,  89 
heat   treatment  in  unequal 

sized  pieces,  97 

—  methods  of,  82-86 

overhead  welding,  105 

springs,    futility    of     weld- 
ing, 93 

teeth,  building  up  of, .96 

vertical  welding,  104 


Wiley  Special  Subject  Catalogues 

For  convenience  a  list  of  fhe  Wiley  Special  Subject 
Catalogues,  envelope  size,  has  been  printed.  These 
are  arranged  in  groups — each  catalogue  having  a  key 
symbol.  (See  special  Subject  List  Below).  To 
obtain  any  of  these  catalogues,  send  a  postal  using 
the  key  symbols  of  the  Catalogues  desired. 


1 — Agriculture.     Animal  Husbandry.    Dairying.     Industrial 
Canning  and  Preserving. 

2— Architecture.       Building.      Masonry. 

3 — Business  Administration  and  Management.     Law. 

Industrial  Processes:   Canning  and  Preserving;    Oil  and  Gas 
Production;  Paint;  Printing;  Sugar  Manufacture;  Textile. 

CHEMISTRY 
4a  General;  Analytical,  Qualitative  and  Quantitative;  Inorganic; 

Organic. 
4b  Electro-  and  Physical;  Food  and  Water;  Industrial;  Medical 

and  Pharmaceutical;  Sugar. 

CIVIL  ENGINEERING 

5a  Unclassified  and  Structural  Engineering. 

5b  Materials  and  Mechanics  of  Construction,  including;  Cement 
and  Concrete;  Excavation  and  Earthwork;  Foundations; 
Masonry. 

5c  Railroads;  Surveying. 

5d  Dams;  Hydraulic  Engineering;  Pumping  and  Hydraulics;  Irri- 
gation Engineering;  River  and  Harbor  Engineering;  Water 
Supply. 

(Over) 


CIVIL  ENGINEERING— Continued 

5e  Highways;  Municipal  Engineering;  Sanitary  Engineering; 
Water  Supply.  Forestry.  Horticulture,  Botany  and 
Landscape  Gardening. 


4> — Design.  Decoration.  Drawing:  General;  Descriptive 
Geometry;  Kinematics;  Mechanical. 

ELECTRICAL  ENGINEERING— PHYSICS 

7 — General  and  Unclassified;  Batteries;  Central  Station  Practice; 
Distribution  and  Transmission;  Dynamo-Electro  Machinery; 
Electro-Chemistry  and  Metallurgy;  Measuring  Instruments 
and  Miscellaneous  Apparatus. 


8 — Astronomy.      Meteorology.      Explosives.      Marine    and 
Naval  Engineering.     Military.     Miscellaneous  Books. 

MATHEMATICS 

<> — General;    Algebra;  Analytic  and  Plane   Geometry;   Calculus; 
Trigonometry;  Vector  Analysis. 

MECHANICAL  ENGINEERING 

lOa  General  and  Unclassified;  Foundry  Practice;  Shop  Practice. 
lOb  Gas  Power  and   Internal  Combustion  Engines;  Heating  and 

Ventilation;  Refrigeration. 
lOc  Machine  Design  and  Mechanism;  Power  Transmission;  Steam 

Power  and  Power  Plants;  Thermodynamics  and  Heat  Power. 
11 — Mechanics.  

12 — Medicine.  Pharmacy.  Medical  and  Pharmaceutical  Chem- 
istry. Sanitary  Science  and  Engineering.  Bacteriology  and 
Biology. 

MINING  ENGINEERING 

13 — General;  Assaying;  Excavation,  Earthwork,  Tunneling,  Etc.; 
Explosives;  Geology;  Metallurgy;  Mineralogy;  Prospecting; 
Ventilation. 


14  DAY  USE 

RETURN  TO  DESK  FROM  WHICH  BORROWED 

LOAN  DEPT. 

This  book  is  due  on  the  last  date  stamped  below, 
or  on  the  date  to  which  renewed.  Renewals  only: 

Tel.  No.  642-3405 

Renewals  may  be  made  4  days  prior  to  date  due. 
Renewed  books  are  subject  to  immediate  recall. 


JAN  26197348 


OCT 


LD21A-40m-3,'72 
(Qll73BlO)476-A-32 


General  Library 

University  of  California 

Berkeley 


163 


423684 


'  :*•'*' 


